Download pdf - Car Ride 2014

Transcript
Page 1: Car Ride 2014

Welcome to Adams/Car Ride

Page 2: Car Ride 2014

Adams/Car RideIntroduction

36

IntroductionAdams/Car Ride, part of the Adams 2014® suite of software, is a plugin to Adams/Car. You can use Adams/Car Ride to model and simulate the ride quality of ground vehicles. It contains modeling elements important for ride quality that you can use in Adams/Car models. You can also analyze the modeling elements independently from other systems using a modeling-element test rig.

In addition, Adams/Car Ride includes a four-post test rig for four-wheeled Adams/Car vehicle models. The four-post test rig supports a variety of time-domain analyses, as well as frequency-domain analyses with Adams/Vibration.

About Adams/Car RideUsing Adams/Car Ride, you can quickly create Adams/Car assemblies of suspensions and full vehicles, including Adams/Car Ride-provided components important for ride quality, and then analyze them to understand their performance and behavior.

The Adams/Car Ride components are:

• Monroe damper

• Hydromount

• Frequency-dependent bushing

You can analyze each component independently from other systems using a component test rig. You can also use a parameter identification tool for the hydromount component, to quickly determine model parameters that will accurately reproduce test data.

Using the Adams/Car Ride four-post test rig for four-wheeled Adams/Car vehicle models you can simulate a vehicle traveling over a rough road or simulate a vehicle on a real four-post shaker test machine. You can play displacement or force RPC III file data into the test rig, make your own bumps with table-lookup functions and drive over them, or create and drive over a road-profile surface using a mathematical model for generating road roughness. In the time domain, the four-post test rig also supports sinusoidal sweeps (displacement, velocity, acceleration, or force) and arbitrary Adams/Solver functions.

Learn more about Referencing Test Data.

Benefits of Adams/Car RideAdams/Car Ride enables you to work faster and smarter, letting you have more time to study and understand how design changes affect vehicle performance.

Using Adams/Car Ride you can:

• Explore the performance of your design and refine your design before building and testing a physical prototype.

Page 3: Car Ride 2014

37Welcome to Adams/Car RideIntroduction

• Analyze design changes much faster and at a lower cost than physical prototype testing would require. For example, you can change springs with a few mouse clicks instead of waiting for a mechanic to install new ones in your physical prototype before re-evaluating your design.

• Vary the kinds of analyses faster and more easily than if you had to modify instrumentation, test fixtures, and test procedures.

• Work in a more secure environment without the fear of losing data from instrument failure or losing testing time because of poor weather conditions.

• Run analyses and what-if scenarios without the dangers associated with physical testing.

• Perform a repeatable set of tests on a global basis, ensuring that you work with common data, tests, and, most important, results.

Starting Adams/Car RideBecause Adams/Car Ride is a plugin to Adams/Car, you first start Adams/Car and then load Adams/Car Ride.

In the Windows environment, you start Adams/Car from the Start button. In the Linux environment, you start Adams/Car from the Adams Toolbar. For information, see the Running and Configuring online help.

To start Adams/Car Ride:

1. Start Adams/Car as explained in Starting Adams/Car.

2. From the Tools menu, select Plugin Manager.

3. In the list of plugin names, find Adams/Car Ride, and then select one or both of the following:

• Load - Loads Adams/Car Ride in the current session.

• Load at Startup - Instructs Adams/Car to load Adams/Car Ride in all future Adams/Car sessions.

4. Select OK.

Adams/Car loads Adams/Car Ride. The interface now includes a new menu, Ride.

Page 4: Car Ride 2014

Adams/Car RideRunning Analyses

38

Running Analyses

Introducing AnalysesAdams/Car Ride allows you to create virtual prototypes of vehicle subsystems, and analyze the virtual prototypes much like you would analyze the physical prototypes.

Using Adams/Car Ride to analyze a virtual prototype is much like requesting a test of a physical prototype. When testing in Adams/Car Ride, you specify the following:

• The virtual prototype to be tested - You specify the virtual prototype by opening or creating an assembly that contains the appropriate components, or subsystems, that make up the prototype. For example, you create a full-vehicle assembly containing suspension, steering, body, brakes, wheels, and so on.

• The kind of Analysis you'd like performed - Depends on the type of model and test rig that you have opened. You can perform analyses of components (using the component test rig), fourpost and vibration analyses (using the fourpost test rig).

• The analysis inputs to be used - You specify the inputs to the analysis by typing them directly into an analysis dialog box or by selecting a loadcase file that contains the desired inputs from an Adams/Car Ride database. Learn about Loadcase Files.

After specifying the prototype assembly and its analysis, Adams/Car Ride, like your company’s testing department, applies the inputs that you specified and records the results. To understand how your prototype behaved during the analysis, you can plot the results. After viewing the results, you can modify the prototype and analyze it again to see if your modifications improved its behavior.

Each kind of analysis that you perform requires a minimum set of subsystems. For example, a full-vehicle analysis requires front and rear suspension subsystems, front and rear wheel subsystems, one steering subsystem, and one body subsystem. Before you can create an assembly and perform an analysis in Adams/Car Ride, you must open or create the minimum set of subsystems required.

Setting up Component AnalysesYou can use a component analysis to calculate the dynamic stiffness and loss angle of a frequency-dependent bushing or damper.

To set up a component analysis:

1. From the Ride menu, point to Component Analysis, and then select Component-Model Test Rig.

2. Press F1 and then follow the instructions in the dialog box help for Component Analysis.

3. Select OK.

Page 5: Car Ride 2014

39Welcome to Adams/Car RideRunning Analyses

Setting up Full-Vehicle AnalysesYou can use a full-vehicle analysis to investigate a car's ride-quality characteristics.

To set up a full-vehicle analysis:

1. From the Ride menu, point to Full-Vehicle Analysis, and then select Four-Post Test Rig.

2. Press F1 and then follow the instructions in the dialog box help for Full-Vehicle Analysis: ARIDE_FOUR_POST_TESTRIG.

3. Select OK.

Setting up Full-Vehicle Vibration AnalysesYou can use a full-vehicle vibration analysis to analyze the behavior of your linearized vehicle model in the frequency domain. This includes analyses of vibration transmission frequency responses, natural frequencies, mode shapes, and damping ratios.

To set up a vibration full-vehicle analysis:

1. From the Ride menu, point to Full-Vehicle Vibration Analysis, and then select Four-Post Test Rig.

2. Press F1 and then follow the instructions in the dialog box help for Full-Vehicle Vibration Analysis: ARIDE_FOUR_POST_TESTRIG.

3. Select OK.

Controlling Analysis Output FilesYour template-based product lets you control the type and content of files an analysis outputs. You can specify whether an analysis outputs a graphics file or results file. Graphics files contain time-dependent data describing the position and orientation of each part in the model. Results files contain a basic set of state variable information that Adams/Solver calculates during a simulation.

Your template-based product automatically reads the files that an analysis outputs.

If any subsystems within the assembly being analyzed contain flexible bodies, your template-based product automatically outputs a results file, regardless of the specifications you made.

To specify analysis output files:

1. From the Settings menu, point to Solver, and then select Output Files.

The Output Files dialog box appears.

2. Select the types of files you want to output.

3. Select OK.

Page 6: Car Ride 2014

Adams/Car RideRunning Analyses

40

Setting up Full-Vehicle A2N Analyses (A2N Export)You can use a full-vehicle a2n analysis for exporting Adams linearized model to Nastran as a whitebox or blackbox. In blackbox, Mass, Stiffness and Damping matrices of your linearized vehicle model are exported in order to provide a Modal and/or Frequency Response Analysis in the FE code. While in whitebox, the linearized model is exported as element to element. Referring to Adams/Vibration help for full details, using Adams/Vibration - Adams2Nastran (A2N Export) feature, you can define the operating point at which you want to export linearized model as whitebox or blackbox and then performing Nastran modal or frequency response analysis: the operating point has been achieved running Adams/Solver, taking into account all the nonlinearities of the system and with the possibility to easily change any parameter or variable for exploring different model configuration and, consequently, to easily recreate full Nastran equivalent model. In blackbox, the Mass, Stiffness and Damping matrices are exported as Nastran DMIG and connected to the system using MPC (Multi Point Constraint) while the location of input channels and output channels (Adams Markers) are exported as Nastran GRIDs and generalized degrees of freedom as SPOINTs.

The feature is limited in the sense that A2N input and output channels are automatically created, located and defined and the user can only decide actuator force values and phases, type of Nastran analysis (Modal or FRF), and how many Nastran subcases have to be created.

It has been provided an embedded and limited solution principally for showing the capability of Adams2Nastran feature. A more complete solution will be provided with the next Adams releases.

To set up a A2N full-vehicle analysis:

1. From the Ride menu, point to Full-Vehicle Vibration Analysis, and then select A2N Export.

2. Press F1 and then follow the instructions in the dialog box help for Full-Vehicle Vibration Analysis: A2N Export.

3. Select OK.

Setting up ISO Ride IndexIt has been proven that vibration results in musculoskeletal disorders of the hand and arms, the neck and the back. There are two types of occupational vibration: segmental and whole body. Segmental vibration is transmitted through the hands and arms; while to whole body vibration (WBV) is transmitted through the body's supporting surfaces such as the legs, the back and the buttocks. Human bodies are exposed to WBV from various sources such as standing on a vibration platform, floor surface, driving, construction, manufacturing and transportation. Along with musculoskeletal problems, exposure to occupational whole body vibration also presents a health risk to the psychomotor, physiological, and psychological systems of the body.

The primary purpose here is to provide computational means for quantifying WBV as described in ISO 2631/1 procedure in relation to: human health, comfort and perception. Response to WBV depends on the frequency of vibration, acceleration (or magnitude) of vibration, number of contact points and the exposure time.

Page 7: Car Ride 2014

41Welcome to Adams/Car RideRunning Analyses

To set up a ISO Ride Index for full-vehicle analysis:

1. From the Ride menu, point to Full-Vehicle Analysis, and then select ISO Ride Index.

2. Press F1 and then follow the instructions in the dialog box help for ISO Ride Index.

3. Select OK.

To calculate Ride Index for Full-Vehicle Vibration Analysis:

1. From the Ride menu, point to Full-Vehicle Vibration Analysis, and then select ISO Ride index.

2. Press F1 and then follow the instructions in the dialog box help for ISO Ride Index.

3. Select OK.

Examples of Ride Index

Example 1: Health analysis with zero contribution from X and Y direction.

This application of ride index to health concerns the effects of periodic, random and transient vibration on the health of persons in normal health exposed to whole-body vibration during travel, at work and during leisure activities. It applies primarily to seated persons, since the effects of vibration on the health of persons standing, reclining or recumbent are not known.

The guidance is applicable to vibration in the frequency range 0, 5 Hz to 80 Hz which is transmitted to the seated body as a whole through the seat pan. Whole-body vibration exposure may also worsen certain endogenous pathologic disturbances of the spine. Although a dose-effect relationship is generally assumed, there is at present no quantitative relationship available. With a lower probability, the digestive system, the genital/urinary system, and the female reproductive organs are also assumed to be affected.

It generally takes several years for health changes caused by whole-body vibration to occur. It is therefore important that exposure measurements are representative of the whole exposure period.

Evaluation of vibration

The weighted RMS acceleration shall be determined for each axis (x, y and z) of translational vibration on the surface which supports the person. The assessment of the effect of a vibration on health shall be made independently along each axis. The assessment of the vibration shall be made with respect to the highest frequency-weighted acceleration determined in any axis on the seat pan. The frequency weighting shall be applied for seated persons as follows with the multiplying factors k as Indicated:

X-axis: wd, k = 1.4

Y-axis: wd, k = 1.4

Z-axis: wk, k = 1.0

Time Domain logic array of RIDE_WARMS for Full-Vehicle Analysis

Seat Surface: Logic = {"TIME", "Wd", "Wd", "Wk"}Seat Back: Logic = {"TIME", "Wc", "Wu", "Wu"}Feet: Logic = {"TIME", "Wu", "Wu", "Wu"}

Page 8: Car Ride 2014

Adams/Car RideRunning Analyses

42

Frequency Domain logic array of RIDE_WARMS for Full-Vehicle Vibration Analysis

Seat Surface: Logic = {"FREQ", "Wd", "Wd", "Wk"}Seat Back: Logic = {"FREQ", "Wc", "Wu", "Wu"}Feet: Logic = {"FREQ", "Wu", "Wu", "Wu"}

Note: When vibration in two or more axes is comparable, the vector sum is sometimes used to estimate health risk.

Page 9: Car Ride 2014

43Welcome to Adams/Car RideRunning Analyses

Page 10: Car Ride 2014

Adams/Car RideRunning Analyses

44

Guidance to Health

There are not sufficient data to show a quantitative relationship between vibrations expose effects. Hence, it is not possible to assess whole-body vibration in terms of the probability exposure magnitudes and durations. For recommendation that are mainly based on exposures in the range of 4 h to 8 h, please refer to ISO 2631-1.

Example 2: Comfort analysis.

The comfort and perception concerns the estimation of the effect of vibration on the comfort of persons in normal health who exposed to whole-body periodic, random and transient vibration during travel, at work or during leisure activities are for the comfort of seated persons this clause applies to periodic, random and transient vibration in the frequency range 0, 5 Hz to 80 Hz which occurs in all six axes on the seat pan (three translational: x-axis, y-axis and z-axis and three rotational: r,-axis, r,-axis and r,-axis).

It also applies to the three translational axes (x, y and z) at the seat-back and feet of seated persons (see figure below). For the comfort of standing and recumbent persons guidance is provided for periodic, random and transient vibration occurring in the three translational (x, y and z) axes on the principal surface supporting the body. The evaluation procedures make it possible to estimate (from the vibration magnitude, frequency and direction) the likely relative effects on comfort of different types of vibration.

Evaluation of vibration

There is no conclusive evidence to support a universal time dependence of vibration effects on comfort. The weighted RMS acceleration shall be determined for each axis of translational vibration (x-, y- and z-axes) at the surface which supports the person. Frequency weightings used for the prediction of the effects of vibration on comfort are Wc, Wd, We, Wj and Wk. These weightings should be applied as follows with the multiplying factors k as indicated.

a. For seated persons:

X-axis (supporting seat surface vibration): Wd, kx = 1

Page 11: Car Ride 2014

45Welcome to Adams/Car RideRunning Analyses

Y-axis (Supporting Seat Surface vibration): Wd, ky = 1

Z-axis (Supporting Seat Surface vibration): Wk, kz = 1

In some environments, the comfort of a seated person may be affected by rotational vibration on the seat, by vibration of the backrest or by vibration at the feet. Vibration at these positions may be assessed using the following frequency weightings:

rx,-axis on supporting seat surface: We, krx = 0.63 m/rad

ry,-axis on supporting seat surface: We, kry = 0.4 m/rad

rz,-axis on supporting seat surface: We, krz = 0.2 m/rad

X-axis on the backrest: WC, kx = 0.8

Y-axis on the backrest: Wd, ky = 0.5

Z-axis on the backrest: Wd, kz = 0.4

X-axis at the feet: Wk, kx = 0.25

Y-axis at the feet: Wk, ky = 0.25

Z-axis at the feet: Wk, kz = 0.4

b. For standing persons:

X-axis (floor vibration): Wd, kx = 1

Y-axis (floor vibration): Wd, ky = 1

Z-axis (floor vibration): Wk, kz = 1

c. For recumbent persons, when measuring under the pelvis:

Horizontal axes: Wd, ky and kz = 1

Vertical axis: Wk, kx = 1

Time Domain logic array of RIDE_WARMS for Full-Vehicle Analysis

Seat Surface: x-y-z axis Logic = {"TIME", "Wd", "Wd", "Wk"}Seat Surface: rx-ry-rz axis Logic = {"TIME", "We", "We", "We"}Seat Back: Logic = {"TIME", "Wc", "Wd", "Wd"}Feet (sitting): Logic = {"TIME", "Wk", "Wk", "Wk"}Standing Vertical Recumbent (except head): Logic = {"TIME", "Wu", "Wu", "Wk"}Standing Horizontal Recumbent: Logic = {"TIME", "Wd", "Wd", "Wu"}Vertical recumbent (head): Logic = {"TIME", "Wj", "Wj", "Wj"} Vertical recumbent (head, under pelvis): Logic = {"TIME", "Wk", "Wd", "Wd"}

Frequency Domain logic array of RIDE_WARMS for Full-Vehicle Vibration Analysis

Seat Surface: x-y-z axis Logic = {"FREQ", "Wd", "Wd", "Wk"}Seat Surface: rx-ry-rz axis Logic = {"FREQ", "We", "We", "We"}Seat Back: Logic = {"FREQ", "Wc", "Wd", "Wd"}Feet (sitting): Logic = {"FREQ", "Wk", "Wk", "Wk"}Standing Vertical Recumbent (except head): Logic = {"FREQ", "Wu", "Wu", "Wk"}

Page 12: Car Ride 2014

Adams/Car RideRunning Analyses

46

Standing Horizontal Recumbent: Logic = {"FREQ", "Wd", "Wd", "Wu"}Vertical recumbent (head): Logic = {"FREQ", "Wj", "Wj", "Wj"} Vertical recumbent (head, under pelvis): Logic = {"FREQ", "Wk", "Wd", "Wd"}

Guidance for comfort

Acceptable values of vibration magnitude for comfort depend on many factors which vary with each application. The following values give approximate indications of likely reactions to various magnitudes of overall vibration total values in public transport. However, as stated before, the reactions at various magnitudes depend on passenger expectations with regard to trip duration and the type of activities passengers expect to accomplish (for example, reading, eating, writing, and so on.) and many other factors (acoustic noise, temperature, and so on.).

Less than 0.315 m/s2 not uncomfortable

0.315 m/s2 to 0.63 m/s2 a little uncomfortable

Page 13: Car Ride 2014

47Welcome to Adams/Car RideRunning Analyses

With respect to comfort and/or discomfort reactions to vibration in residential and commercial buildings, IS0 2631-1 and IS0 2631-2 should be consulted. Experience in many countries has shown that occupants of residential buildings are likely to complain if the vibration magnitudes are only slightly above the perception threshold.

Example 3: Perception analysis.

For the random perception of vibration by standing, sitting and recumbent persons, guidance is provided for vibration occurring in the three translational periodic axes (x, y and z) on the principal surface supporting the body.

Evaluation of vibration

The weighted RMS acceleration shall be determined for each axis (x, y and z) on the principal surface supporting the body. The assessment of the perceptibility of the vibration shall be made with respect to highest weighted RMS acceleration determined in any axis at any point of contact ant any time.

The frequency weightings, Wk for vertical vibration and Wd for horizontal vibration, are used for the prediction of the perceptibility of vibration. There weightings may be applied to the following combinations of posture and vibration axis:

X-, y- and z-axes on a supporting seat surface for sitting person, kx=ky=kz=1

X-, y- and z-axes on a floor beneath a standing person, kx=ky=kz=1

X-, y- and z-axes on a surface supporting a recumbent person (except head), kx=ky=kz = 1

Time Domain logic array of RIDE_WARMS for Full-Vehicle Analysis

Seat Surface: x-y-z axis Logic = {"TIME", "Wd", "Wd", "Wk"}Seat Surface: rx-ry-rz axis Logic = {"TIME", "We", "We", "We"}Seat Back: Logic = {"TIME", "Wc", "Wu", "Wu"}Standing Horizontal Recumbent: Logic = {"TIME", "Wd", "Wd", "Wu"}Vertical recumbent (head): Logic = {"TIME", "Wj", "Wj", "Wj"} Vertical recumbent (head, under pelvis): Logic = {"TIME", "Wk", "Wd", "Wd"}

Frequency Domain logic array of RIDE_WARMS for Full-Vehicle Vibration Analysis

Seat Surface: x-y-z axis Logic = {"FREQ", "Wd", "Wd", "Wk"}Seat Surface: rx-ry-rz axis Logic = {"FREQ", "We", "We", "We"}Seat Back: Logic = {"FREQ", "Wc", "Wu", "Wu"}Standing Vertical Recumbent (except head): Logic = {"FREQ", "Wu", "Wu", "Wk"}Standing Horizontal Recumbent: Logic = {"FREQ", "Wd", "Wd", "Wu"}

0.5 m/s2 to 1 m/s2 fairly uncomfortable

0.8 m/s2 to 1.6 m/s2 uncomfortable

1.25 m/s2 to 2.5 m/s2 very uncomfortable

Greater than 2 m/s2 extremely uncomfortable

Page 14: Car Ride 2014

Adams/Car RideRunning Analyses

48

Vertical recumbent (head): Logic = {"FREQ", "Wj", "Wj", "Wj"} Vertical recumbent (head, under pelvis): Logic = {"FREQ", "Wk", "Wd", "Wd"}

Guidance for perception

Fifty percent of alert, fit persons can just detect a Wk weighted vibration with a peak magnitude of 0.015

m/s2. There is a large variation between individuals in their ability to perceive vibration. When the

median perception threshold is approximately 0.015 m/s2, the inter-quartile range of responses may

extend from about 0.0l m/s2 to 0.02 m/s2 peak. The perception threshold decreases slightly with increases in vibration duration up to one second and very little with further increases in duration. Although the perception threshold does not continue to decrease with increasing duration, the sensation produced by vibration at magnitudes above threshold may continue to increase.

Page 15: Car Ride 2014

49Welcome to Adams/Car RideExamples of Using Adams/Car Ride

Examples of Using Adams/Car RideThe following Adams/Car Ride examples are available:

• Getting Started Using Adams/Car Ride

• Example Input Hydromount Property File

• Example Output Hydromount Property File

• Example Input Bushing Property File

• Example Output Bushing Property File

Page 16: Car Ride 2014

Adams/Car RideExamples of Using Adams/Car Ride

50

Page 17: Car Ride 2014

Working with Components

Page 18: Car Ride 2014

Adams/Car RideGeneral Frequency-Dependent Element

52

General Frequency-Dependent Element

Component Name

ac_general_f_d_element

Source Directory

/$MDI_RIDE_PLUGIN/template_builder/udes/ac_general_f_d_element

Description

This component is a six degrees-of-freedom force, having each component modeled by three linear springs and three linear dampers; the elements of the single component can be connected in different ways and eventually deactivated to create the following:

1. Linear Pfeffer element (one spring in parallel with a series damper - parallel spring damper)

2. Simple FD damper (one spring in parallel with a series spring damper)

3. Simple FD bushing (one spring in series with a parallel spring damper)

4. General element (one parallel spring damper in parallel with a series of two parallel spring dampers)

You can also specify a preload for each force component.

Using the replace feature in Standard Interface, you can create a general frequency-dependent element as a replacement for a standard Adams/Car bushing. In the replacement element dialog box, select a property file, setting preload, and activity for each component.

Specifications

.ARIDE.forcess.ac_general_f_d_element

Parameters

Parameter: Type: Function:

property_file string variable Name of property file

X_type string variable X component element type

T_preload_x real variable Element translational preload x

X_C1 real variable

X_K1 real variable

X_C2 real variable

X_K2 real variable

X_C3 real variable

Page 19: Car Ride 2014

53Working with ComponentsGeneral Frequency-Dependent Element

X_K3 real variable

Y_type string variable Y component element type

T_preload_y real variable Element translational preload y

Y_C1 real variable

Y_K1 real variable

Y_C2 real variable

Y_K2 real variable

Y_C3 real variable

Y_K3 real variable

Z_type string variable Z component element type

T_preload_z real variable Element translational preload z

Z_C1 real variable

Z_K1 real variable

Z_C2 real variable

Z_K2 real variable

Z_C3 real variable

Z_K3 real variable

AX_type string variable AX component element type

R_preload_x real variable Element rotational preload x

AX_C1 real variable

AX_K1 real variable

AX_C2 real variable

AX_K2 real variable

AX_C3 real variable

AX_K3 real variable

AY_type string variable AY component element type

R_preload_y real variable Element rotational preload y

AY_C1 real variable

AY_K1 real variable

AY_C2 real variable

AY_K2 real variable

AY_C3 real variable

AY_K3 real variable

Parameter: Type: Function:

Page 20: Car Ride 2014

Adams/Car RideGeneral Frequency-Dependent Element

54

Input Parameters

Output Parameters

none

Objects:

AZ_type string variable AZ component element type

R_preload_z real variable Element rotational preload z

AZ_C1 real variable

AZ_K1 real variable

AZ_C2 real variable

AZ_K2 real variable

AZ_C3 real variable

AZ_K3 real variable

X_active integer variable

Y_active integer variable

Z_active integer variable

AX_active integer variable

AY_active integer variable

AZ_active integer variable

I_geo_marker object variable

J_geo_marker object variable

geo_radius real variable

geo_length real variable

Bushing_jfloat object variable

Input parameter: Type: Function:

i_marker object variable Action marker

j_marker object variable Reaction marker

Object: Type:

Force single_component_force

Gse general_state_equation

Parameter: Type: Function:

Page 21: Car Ride 2014

55Working with ComponentsGeneral Frequency-Dependent Element

Request Definition

disp_request

U_var_x state variable

U_var_y state variable

U_var_z state variable

U_var_ax state variable

U_var_ay state variable

U_var_az state variable

State_array X_state_array

Output_array Y_output_array

Ic_array IC_array

Input_array U_input_array

KC_array IC_array

Disp_Request request

Velo_Request request

Acc_Request request

Force_Request request

Component name: Component units: Definition:

DX Length Distance between i_marker and j_marker along j_marker X

DY Length Distance between i_marker and j_marker along j_marker Y

DZ Length Distance between i_marker and j_marker along j_marker Z

AX Angle Angle between i_marker and j_marker X

AY Angle Angle between i_marker and j_marker Y

AZ Angle Angle between i_marker and j_marker Z

Object: Type:

Page 22: Car Ride 2014

Adams/Car RideGeneral Frequency-Dependent Element

56

velo_request

acc_request

Component name: Component units: Definition:

VX Velocity Relative velocity between i_marker and j_marker along j_marker X

VY Velocity Relative velocity between i_marker and j_marker along j_markerY

VZ Velocity Relative velocity between i_marker and j_marker along j_marker Z

WX Angular Velocity Relative angular velocity between i_marker and j_marker X

WY Angular Velocity Relative angular velocity between i_marker and j_marker Y

WZ Angular Velocity Relative angular velocity between i_marker and j_marker Z

Component name: Component units: Definition:

AX Acceleration Relative acceleration between i_marker and j_marker along j_marker X

AY Acceleration Relative acceleration between i_marker and j_marker along j_marker Y

AZ Acceleration Relative acceleration between i_marker and j_marker along j_marker Z

WDTX Angular Acceleration Relative angular acceleration between i_marker and j_marker X

WDTY Angular Acceleration Relative angular acceleration between i_marker and j_marker Y

WDTZ Angular Acceleration Relative angular acceleration between i_marker and j_marker Z

Page 23: Car Ride 2014

57Working with ComponentsGeneral Frequency-Dependent Element

force_request

Design Parameters

Macros

Create Macro: (call: acar template_builder instance ac_general_f_d_element create) Adams/Car Ride executes this macro when you create an instance of the definition ac_general_f_d_element.

Modify Macro: (call: acar template_builder instance ac_general_f_d_element modify) Adams/Car Ride executes this macro when you modify an instance of the definition ac_general_f_d_element.

Component name: Component units: Definition:

FX Force Force between i_marker and j_marker along j_marker X

FY Force Force between i_marker and j_marker along j_marker Y

FZ Force Force between i_marker and j_marker along j_marker Z

TX Torque Torque between i_marker and j_marker X

TY Torque Torque between i_marker and j_marker Y

TZ Torque Torque between i_marker and j_marker Z

Parameter: Type: Function:

scaling_factor real variable Scaling factor (DOE)

Page 24: Car Ride 2014

Adams/Car RideSingle Component Frequency-Dependent Elements

58

Single Component Frequency-Dependent Elements

Component Name

ac_single_f_d_element

Source Directory

/$MDI_RIDE_PLUGIN/template_builder/udes/ac_single_f_d_element

Description

This component is a one degree of freedom force modeled by three linear springs and three linear dampers; the elements may be connected in different ways and eventually deactivated in order to create the following:

1. Linear Pfeffer element (one spring in parallel with a series damper - parallel spring damper)

2. Simple FD damper (one spring in parallel with a series spring damper)

3. Simple FD bushing (one spring in series with a parallel spring damper)

4. General element (one parallel spring damper in parallel with a series of two parallel spring dampers)

Using the replace feature in Standard Interface, you can create a general frequency-dependent element as a replacement for a standard Adams/Car bushing. In the replacement element dialog box, select a property file and setting preload for the component.

Specifications

.ARIDE.forcess.ac_single_f_d_element

Parameters

Parameter: Type: Function:

property_file string variable Name of property file

preload real variable Element preload

type string variable Element type

scale_factor real variable Force scale factor

geo_scale real variable Geometry scale

Page 25: Car Ride 2014

59Working with ComponentsSingle Component Frequency-Dependent Elements

Input Parameters

Output Parameters

none

Objects:

Input parameter: Type: Function:

i_marker object variable Action marker

j_marker object variable Reaction marker

Object: Type:

C1 real variable

K1 real variable

C2 real variable

K2 real variable

C3 real variable

K3 real variable

F01 real variable

F03 real variable

Uvar state variable

Outvark1c1 state variable

State_array X_state_array

Output_array Y_output_array

Ic_array IC_array

Input_array U_input_array

Force single_component_force

Gse general_state_equation

Request request

Graphic geometry

Dm_calc real variable

Page 26: Car Ride 2014

Adams/Car RideSingle Component Frequency-Dependent Elements

60

Request Definition

request

user (904,i_marker,j_marker)

Design Parameters

Macros

Create Macro: (call: acar template_builder instance ac_single_f_d_element create) Adams/Car Ride executes this macro when you create an instance of the definition ac_single_f_d_element.

Modify Macro: (call: acar template_builder instance ac_single_f_d_element modify) Adams/Car Ride executes this macro when you modify an instance of the definition ac_single_f_d_element.

Component name: Component units: Definition:

Displacement length Distance between i_marker and j_marker

Velocity velocity Relative velocity of i_marker and j_marker

Force force Force between i_marker and j_marker

Parameter: Type: Function:

scaling_factor real variable Scaling factor (DOE)

Page 27: Car Ride 2014

61Working with ComponentsFrequency Bushing

Frequency Bushing

Component Name

ac_frequency_bushing

Source Directory

/$MDI_RIDE_PLUGIN/template_builder/udes/ac_frequency_bushing

Description

This component is based on a GFORCE element. The damping coefficients of the GFORCE are interpreted as the loss angles. The forces in the x- and y-plane and the moments along the x- and y-axis are interpolated elliptical. The z force and moment are mapped directly from the splines.

Specifications

.ARIDE.parts.ac_frequency_bushing

Parameters

Parameter: Type: Function:

property_file string variable name of property file

t_preload_x real variable translational preload

t_preload_y real variable translational preload

t_preload_z real variable translational preload

r_preload_x real variable rotational preload

r_preload_y real variable rotational preload

r_preload_z real variable rotational preload

t_offset_x real variable translational offset

t_offset_y real variable translational offset

t_offset_z real variable translational offset

r_offset_x real variable rotational offset

r_offset_y real variable rotational offset

r_offset_z real variable rotational offset

i_geoMarker marker geometry ref marker

j_geoMarker marker geometry ref marker

geoRadius real variable geometry radius

geoLength real variable geometry length

Page 28: Car Ride 2014

Adams/Car RideFrequency Bushing

62

Input Parameters

Output Parameters

none

Objects

Request Definition

disp_request

user (0,1,i_marker,j_marker,gforce)

Input parameter: Type: Function:

i_marker object variable action marker

j_marker object variable marker whose parent is the reaction part and reference marker

Object: Type: Function:

data_array Adams array array to pass the preloads, offsets, damping coefficients to the field subroutine

fx_spline Adams spline force spline

fy_spline Adams spline

fz_spline Adams spline

tx_spline Adams spline torque spline

ty_spline Adams spline

tz_spline Adams spline

i_graphic revolution graphics on I part

j_graphic cylinder graphics on J part

disp_request request displacement request subroutine ROUTINE = aride_solver::reqaride

velo_request request velocity request subroutine ROUTINE = aride_solver::reqaride

force_request request force request subroutine ROUTINE = aride_solver::reqaride

gforce gforce frequency dependent bushing gforce subroutine as part of the plugin ride_solver::FREQUENCY_BUS

Component name: Component units: Definition:

dx length x-distance between i_marker and j_marker

dy length y-distance between i_marker and j_marker

Page 29: Car Ride 2014

63Working with ComponentsFrequency Bushing

velo_request

user (0,2,i_marker,j_marker,gforce)

force_request

user (0,6,i_marker,j_marker,gforce)

dz length z-distance between i_marker and j_marker

dm length magnitude

ax angle angle about x

ay angle angle about y

az angle angle about z

amag angle magnitude

Component name: Component units: Definition:

vx velocity x-velocity between i_marker and j_marker

vy velocity y-velocity between i_marker and j_marker

vz velocity z-velocity between i_marker and j_marker

vm velocity magnitude

wx angular_velocity

wy angular_velocity

wz angular_velocity

wm angular_velocity magnitude

Component name: Component units: Definition:

bushing_fx force x-force between i_marker and j_marker

bushing_fy force y-force between i_marker and j_marker

bushing_fz force z-force between i_marker and j_marker

fm force magnitude

bushing_tx torque

bushing_ty torque

bushing_tz torque

tm torque magnitude

Component name: Component units: Definition:

Page 30: Car Ride 2014

Adams/Car RideFrequency Bushing

64

Subsystem Parameters

Design Parameters

Macros

Create Macro: (call: acar template_builder instance ac_frequency_bushing create) Adams/Car Ride executes this macro when you create an instance of the definition ac_frequency_bushing.

Modify Macro: (call: acar template_builder instance ac_frequency_bushing modify) Adams/Car Ride executes this macro when you modify an instance of the definition ac_frequency_bushing.

Delete Macro: (call: acar template_builder instance ac_frequency_bushing delete) This macro deletes all the entities which have been created exclusively for the instance.

See About the Bushing Model for more information.

Top level: Sub level:

property_file

t_preload_(x-z)

r_preload_(x-z)

t_offset_(x-z)

r_offset_(x-z)

Parameter: Type: Function:

fx_scaling_factor real variable scaling factor (DOE)

fy_scaling_factor real variable scaling factor (DOE)

fz_scaling_factor real variable scaling factor (DOE)

tx_scaling_factor real variable scaling factor (DOE)

ty_scaling_factor real variable scaling factor (DOE)

tz_scaling_factor real variable scaling factor (DOE)

Page 31: Car Ride 2014

65Working with ComponentsGeneral Bushing

General Bushing

Component Name

ac_general_bushing

Source Directory

/$MDI_RIDE_PLUGIN/template_builder/udes/ac_general_bushing

Description

This component is based on a GFORCE element such as the standard ac_bushing. The forces in all six directions are orthogonal and can be coupled in rectangular, cylindrical or spherical ways. The total force from this element is sum of static spline force, TFSISO force, Bouc-Wen hysteresis force, preload and viscous damping force.

Specifications

.ARIDE.parts.ac_general_bushing

Parameters

Parameter: Type: Function:

property_file string variable name of property file

t_preload_x real variable translational preload

t_preload_y real variable translational preload

t_preload_z real variable translational preload

r_preload_x real variable rotational preload

r_preload_y real variable rotational preload

r_preload_z real variable rotational preload

t_offset_x real variable translational offset

t_offset_y real variable translational offset

t_offset_z real variable translational offset

r_offset_x real variable rotational offset

r_offset_y real variable rotational offset

r_offset_z real variable rotational offset

i_geoMarker marker geometry ref marker

j_geoMarker marker geometry ref marker

Page 32: Car Ride 2014

Adams/Car RideGeneral Bushing

66

Input Parameters

Output Parameters

none

Objects

geoRadius real variable geometry radius

geoLength real variable geometry length

Input parameter: Type: Function:

i_marker object variable action marker

j_marker object variable marker whose parent is the reaction part and reference marker

Object: Type: Function:

bushing_shape integer value 0 or 1: rectangular coupling

2: cylindrical coupling

3: spherical coupling

gen_coupling integer value 0: Uncouple Bouc-Wen force from linear stiffness force

1: Couple Bouc-Wen force with linear stiffness force

2: Revised Bouc-Wen force with linear stiffness force

(tx-rz)_data_array Adams array Array to pass stiffness and damping types, scales, spline ID, preload, damping and velocity offsets and scales, static spline ID, Bouc-Wen parameters ALPHA, ZETA, OMEGA, K, hysteresis type, hysteresis spline ID/Bouc-Wen DIFF ID, hysteresis/Bouc-Wen force scale, TFSISO output array ID and TFSISO force scale to the subroutine

data_array_(x-az) Adams array array to pass the Bouc-Wen model parameters BETA, GAMMA, A and N to the subroutine

(x-az)_alpha real variable Bouc-Wen parameter

(x-az)_beta real variable Bouc-Wen parameter

(x-az)_gamma real variable Bouc-Wen parameter

Parameter: Type: Function:

Page 33: Car Ride 2014

67Working with ComponentsGeneral Bushing

Request Definition

disp_request

user (905,1,i_marker,j_marker,field) and routine = aride_solver::reqaride

(x-az)_zeta real variable Bouc-Wen parameter

(x-az)_omega real variable Bouc-Wen parameter

(x-az)_a real variable Bouc-Wen parameter

(x-az)_n real variable Bouc-Wen parameter

(x-az)_num real variable TFSISO Numerator array

(x-az)_den real variable TFSISO Denominator array

fx_spline Adams spline Static force spline in x direction

fy_spline Adams spline Static force spline in y direction

fz_spline Adams spline Static force spline in z direction

tx_spline Adams spline Static torque spline in ax direction

ty_spline Adams spline Static torque spline in ay direction

tz_spline Adams spline Static torque spline in az direction

i_graphic revolution graphics on I part

j_graphic cylinder graphics on J part

disp_request request displacement request

velo_request request velocity request

force_request request force request

gforce gforce bushing dependent bushing gforce subroutine as part of the AvSub::FD_BUSHING

Component name: Component units: Definition:

dx length x-distance between i_marker and j_marker

dy length y-distance between i_marker and j_marker

dz length z-distance between i_marker and j_marker

dm length magnitude

ax angle angle about x

ay angle angle about y

Object: Type: Function:

Page 34: Car Ride 2014

Adams/Car RideGeneral Bushing

68

velo_request

user (905,2,i_marker,j_marker,field) and routine = aride_solver::reqaride

force_request

user (905,3,i_marker,j_marker,field) and routine = aride_solver::reqaride

az angle angle about z

amag angle magnitude

Component name: Component units: Definition:

vx velocity x-velocity between i_marker and j_marker

vy velocity y-velocity between i_marker and j_marker

vz velocity z-velocity between i_marker and j_marker

vm velocity magnitude

wx angular_velocity x-angular velocity between i_marker and j_marker

wy angular_velocity y- angular velocity between i_marker and j_marker

wz angular_velocity z- angular velocity between i_marker and j_marker

wm angular_velocity magnitude

Component name: Component units: Definition:

bushing_fx force x-force between i_marker and j_marker

bushing_fy force y-force between i_marker and j_marker

bushing_fz force z-force between i_marker and j_marker

fm force Force magnitude (translational)

bushing_tx torque x-torque between i_marker and j_marker

bushing_ty torque y- torque between i_marker and j_marker

bushing_tz torque z- torque between i_marker and j_marker

tm torque Torque magnitude (rotational)

Component name: Component units: Definition:

Page 35: Car Ride 2014

69Working with ComponentsGeneral Bushing

Subsystem Parameters

Design Parameters

Macros

Create Macro: (call: acar template_builder instance ac_general_bushing create) Adams/Car Ride executes this macro when you create an instance of the definition ac_general_bushing.

Modify Macro: (call: acar template_builder instance ac_general_bushing modify) Adams/Car Ride executes this macro when you modify an instance of the definition ac_general_bushing.

Delete Macro: (call: acar template_builder instance ac_general_bushing delete) This macro deletes all the entities which have been created exclusively for the instance.

About Bushing Property FileTo avoid confusion with the .gbu files, any general bushing can be used in Adams/Car Assembly to calculate the bushing force and behavior but can also be used in IPIT for parameter identification of the bushing parameters out of measurement data. The headings marked below with (**) are used in IPIT during the identification only and the headings marked with (*) are intended to be used in Adams/Car Ride when simulating the bushing force and response.

It should be noted that the IPIT identifies the bushing parameters for one direction at a time only as specified in the GBU file. The following shows a number of important parameters that must be defined in the GBU property file. Please refer to Isolator-Parameter Identification Tool (IPIT) help for further details of each parameter, its meaning and about its default values.

Top level: Sub level:

property_file

t_preload_(x-z)

r_preload_(x-z)

t_offset_(x-z)

r_offset_(x-z)

Parameter: Type: Function:

fx_scaling_factor real variable scaling factor (DOE)

fy_scaling_factor real variable scaling factor (DOE)

fz_scaling_factor real variable scaling factor (DOE)

tx_scaling_factor real variable scaling factor (DOE)

ty_scaling_factor real variable scaling factor (DOE)

tz_scaling_factor real variable scaling factor (DOE)

Page 36: Car Ride 2014

Adams/Car RideGeneral Bushing

70

The block [MDI_HEADER] must be exactly the same in all the .gbu files.

In the block [UNITS] the test data units should be specified. For IPIT the units are fixed to respectively N, mm, kg, degrees and second.

The block [GENERAL] must contain all parameters as listed in the sample file.

• The DEFINITION is always '.aride.attachment.ac_general_bushing'

• The BUSHING_COORDINATE(**) can be x, y, z, ax, ay or az. This parameter it is only used by IPIT and it determines the co-ordinate in which the bushing parameters will be identified.

• BUSHING_SHAPE(*) can be 0 or 1 for rectangular coupling, 2 for cylindrical coupling or 3 for spherical coupling. All these types are supported in Adams/Car Models. IPIT uses rectangular coupling during identification only. Further the bushing coordinate of the identifying direction is required.

• BUSHING_COUPLING can be set to 0 for un-coupled Bouc-Wen force, 1 for coupled Bouc-Wen force or 2 for revised Bouc-Wen force.

The blocks [DAMPING], [PRELOAD] and [OFFSET] are optional.

The blocks [SPLINE_SCALES], [HYST_SCALES] and [TFSISO_SCALES] are compulsory.

The blocks [FX_CURVE], [FY_CURVE], [FZ_CURVE], [TX_CURVE], [TY_CURVE], [TZ_CURVE] are given to supply static splines.

The [BUSHING_PARAMETERS] block supplies the bushing parameters values. Both in an Adams/Car Assembly and IPIT, your bushing force is calculated using these parameters. The IPIT updates these parameters during the identification process.

The blocks [BUSHING_TEST_DATA](**) and [BUSHING_IDENTIFICATION_DATA](**) contain the measured and the identified data. The block [BUSHING_SCALE_DATA](**) contains a scales matrix. These three blocks are used only during the identification process in IPIT.

See Example Bushing Property File.

Page 37: Car Ride 2014

71Working with ComponentsGSE Damper

GSE DamperTo use a GSE damper, you must have a license for Adams/Controls.

Adams's system modeling elements enable the modeling and importing of external dynamic systems. Those elements make it possible for users to define transfer functions, linear state equations, and nonlinear state equations outside of Adams, and then input them for use with Adams. Among those, the general state equation (GSE) is designed to model and import nonlinear external dynamic systems, such as a damper.

The GSE damper provided with Adams/Car Ride illustrates a simple ride-based damper that has been

created within Mathworks® Simulink® and exported using Mathworks RealTime Workshop® (RTW). The GSE damper provides a framework that you can use to import proprietary damper models into Adams/Car Ride.

For more information on importing the object code of the damper, see the guide, Getting Started Using Adams/Controls.

Learn more about GSE dampers:• Scope

• Results

• Parametric Studies

• Solver Background

• Benefits of External Dynamic System Import

Scope

Provided with Adams/Car Ride is a complete set of files that you can use with Mathworks Simulink and Adams/Car Ride to incorporate and test the functionality of the GSE damper. A license of Mathworks Simulink and appropriate compilers is required to carry out this process. If, however, another user provides you with a library (.dll, .so, or .sl, depending on your platform), you will only need a license of Adams/Controls and Adams/Car Ride to run an analysis within Adams.

This topic provides a guide to using the GSE damper component. It does not explain how to use Mathworks Simulink or how to export a library using RTW.

Results

When you create a GSE damper, Adams/Car Ride automatically creates some associated REQUEST statements. These requests measure the displacement, velocity, and force across the damper.

Parametric Studies

As with all elements, in Adams/Car Ride you can study the parametric behavior of components. You can modify a number of parameters for use in Adams/Insight. The parameter data is stored in the corresponding subsystem file.

Page 38: Car Ride 2014

Adams/Car RideGSE Damper

72

Solver Background

A General State Equation (GSE) is an Adams element designed for time-variant, nonlinear, continuous or discrete dynamic systems, which can be mathematically represented as follows:

(1)

(2)

(3)

....

The definition of GSEs contains two portions:

• GSE statement in the model: Provides the interface with Adams model, and specifies the attributes of the imported dynamic system.

• GSE library: A library of code written to the Adams GSE specification. For more information on general state equations, see the online help for Adams/Solver.

Benefits of External Dynamic System Import

Embedding external dynamic systems into Adams allows the use of a unified platform for multi-domain analyses, and provides the following advantages over a cosimulation-based approach:

• Faster speed: Powerful Adams integrators can simulate the stiff combined systems at a speed unmatched by function-evaluation mode in Adams/Controls.

• Higher accuracy: Because the external dynamic systems and the Adams model are incorporated into one formulation, the dynamic coupling between them can be precisely represented, and its effect is taken into account during the simulation. The accuracy achieved with external dynamic systems imported is unparalleled compared to those from cosimulation and function-evaluation mode.

• DOE with Adams/Insight

• Protecting proprietary code: Because the external dynamic systems can be imported in the form of an object file and demand-loaded library, the proprietary code is not exposed.

However, to create both the GSE statement and the demand-load library manually, you need a high level of programming skills and a deep understanding of Adams/Solver. To facilitate the creation of the GSE, an external system import utility is designed as a feature of the GSE damper element to import the external dynamic systems code.

xc·

fc xc u t, ,( )= xc t0( ) xc0=

xdn 1+fd xdn

u t, ,( )= xd t0( ) xd0=

y g xc xd u t, , ,( )=

Page 39: Car Ride 2014

73Working with ComponentsGSE Damper

Control System Import

The Control System Import performs the following steps:

1. Creates a library.

2. Queries the library to be imported for the information used to update the GSE statement of the GSE damper element. The external dynamic system library should provide information, such as number of states, inputs and outputs, and the tunable parameter.

3. Performs an error check to ensure that the external system complies with the standard required by the GSE damper element.

4. Generates a property file in the default writable database, which contains the parameters of your Simulink model.

During the simulation, the demand-loaded library is loaded into and called by Adams/Solver to provide derivatives of states and output for Adams/Solver to integrate.

A set of example files is located in the shared_ride_database.cdb/gse_damper.tbl.

Simulink Damper ModelThis section teaches you how to generate an External System Library (ESL) for a damper designed in MATLAB/Simulink and import them into Adams/Car Ride. Adams/Controls is required to use this feature, and uses a similar, but more generalized process of Control System Import. Please refer Adams/Controls for further details of the general method of importing models from Simulink or Easy5.

A Simulink damper model can be used when you want to model proprietary dampers in Adams. Due to the customized process in Adams/Car Ride, the damper model must have three inputs, in the following order:

• Displacement

• Velocity

• Acceleration between the markers I and J.

Inputs not required by the Simulink model must be terminated with a terminator block. The model must have one output, which is the force from the Simulink modal of the damper to be applied in the Adams model. The inputs and output are in Adams modeling units. The sample Simulink file damper_example_tf.mdl is provided in Aride shared database under gse_damper.tbl folder for demonstration.

Following are the basic steps one has to perform to use Simulink damper in Adams:

• Step One - Replace Damper with GSE_Damper

• Step Two - Export the Plant File for MATLAB

• Step Three - Setup MATLAB

• Step Four - Create Adams Target for Real Time Workshop

Page 40: Car Ride 2014

Adams/Car RideGSE Damper

74

• Step Five - Create Simulink Model

• Step Six -Code Generation of Simulink Damper Model (Control System)

• Step Seven - Select the Damper Library and Simulate

Step One - Replace Damper with GSE_Damper

First you will start Adams/Car and open component test rig, and then perform a Replace operation to create a GSE_Damper.

To start Adams/Car and open component test rig:

1. Launch Adams/Car

2. Load the Adams/Car Ride plug-in, if not already loaded and open the assembly: component_damper_example.asy

3. Use Replace feature in Aride to replace Damper with GSE_damper

(Right click the assembly and select Damper:component_damper_001.das_dar_ride_damper -> Replace)

This is required to create the input and output state variables for the damper model in Simulink

Step Two - Export the Plant File for MATLAB

In this section, you will export the Adams linear and nonlinear plant files to MATLAB.

1. Click the to launch the Adams/Controls Plant Export dialog box.

Page 41: Car Ride 2014

75Working with ComponentsGSE Damper

2. Complete the dialog box as shown below.

3. Click OK

Adams/Controls save the input and output information in a gse_damper.m file under working directory

Step Three - Setup MATLAB

First you will start MATLAB, and then you will create a Simulink model for control system design. You will use the Plant Export.m file to setup MATLAB, as well as the example_damper_tf model files supplied in Aride shared database,

To start MATLAB:

1. Start MATLAB in the same directory as on the model and Simulink files reside.

2. Set up the MEX utility, if not already set.

Enter mex -setup from the MATLAB command window, and then select the appropriate compiler. (see http://simcompanion.mscsoftware.com under Hardware & Software Requirements for a list of supported compilers)

3. At the prompt (>>), enter gse_damper

MATLAB displays the following:

%%% INFO : ADAMS plant actuators names :1 force_state%%% INFO : ADAMS plant sensors names :1 displacement_state2 velocity_state 3 acceleration_state

4. At the prompt, enter who to view the list of variables defined in the files.

MATLAB displays the following relevant information:

ADAMS_cwd ADAMS_pinput ans ADAMS_exec ADAMS_poutput arch ADAMS_host ADAMS_prefix flag ADAMS_init ADAMS_solver_type machine ADAMS_inputs ADAMS_static temp_str

Page 42: Car Ride 2014

Adams/Car RideGSE Damper

76

ADAMS_mode ADAMS_sysdir topdir ADAMS_outputs ADAMS_uy_ids

You can check any of the above variables by entering them at the MATLAB prompt. For example, if you enter Adams_outputs, MATLAB displays all of the outputs defined for your mechanism, that is: ADAMS_outputs = displacement_state!velocity_state!acceleration_state.

Step Four - Create Adams Target for Real Time Workshop

In order to generate the External System Library from the MATLAB/Simulink model, you need to generate some special files for MATLAB/Real-Time Workshop (RTW). You will customize the Makefile template and source code template for Adams, based on the version of MATLAB. Once this is done, you can use the customized template files for other Simulink models.

To create the Real-Time Workshop files for the Adams/Controls model:

1. At the MATLAB prompt (>>), enter setup_rtw_for_adams

This will automatically detect the version of Matlab you are using and then create the makefile template, source code template for Adams. This function will also build template for specific versions of Matlab if desired by entering the desired version token as an argument: setup_rtw_for_adams('<version>')). For help on this, enter setup_rtw_for_adams('h').

You should see the following message for success in this step:

%%% Successfully created files for Adams library export from MATLAB/RTW.

You should also confirm that in your working directory that .tlc and .tmf files were created by this step.

Alternatively, since the function setup_rtw_for_adams also uses process.py, you can still setup using the old method:

(Optional method if not using setup_rtw_for_adams function)

a. Set the MATLAB_ROOT environment variable to the MATLAB installation directory. For example:

• On Windows (DOS shell): set MATLAB_ROOT= c:\matlab78\

• On Linux (c shell): setenv MATLAB_ROOT /usr/matlab_78/

• On Linux (korn shell): export MATLAB_ROOT = /usr/matlab_78/

• Change the directory paths to match your installation.

b. In the directory where your Adams model resides, enter the following command, where $adams_dir is the directory in which Adams is installed:

• On Linux: adams2014 -c python ($adams_dir)/controls/utils/process.py -v 78 exit

• On Windows: adams2014 python ($adams_dir)\controls\utils\process.py -v 78

Alternatively, you can copy the process.py file from the <adams_dir>/controls/utils/ directory on Linux or <adams_dir>\controls\utils\ on Windows to the current directory and issue the following command:

• On Linux: adams2014 -c python process.py -v 78 exit

Page 43: Car Ride 2014

77Working with ComponentsGSE Damper

• On Windows: adams2014 python process.py -v 78

The argument -v 78 stands for MATLAB 7.8 (R2009a).

This command customizes several files from the MATLAB installation for the Adams target and your computer setup. You should notice several new files in your working directory with a .tlc extension and two new files with a .tmf extension. These files required by MATLAB's Real Time Workshop in the steps that follow. For help with process.py, use the -h flag (that is, process.py -h).

Step Five - Create Simulink Model

To create the Simulink template for the control system:

1. Enter setio at the MATLAB prompt.

MATLAB creates a template model with the inport(s) and outport(s) defined, as shown below.

Based on this template, you can design your proprietary damping systems. These files you already copied into the local directory.

Note: The value for MATLAB_ROOT should have no quote, no spaces (on Windows, get short names with command dir /x), and a final slash on the path. For example, if you want to set C:\Program Files\matlab78\ as your MATLAB_ROOT, then do it as: set MATLAB_ROOT= C:\PROGRA~1\matlab78\

Page 44: Car Ride 2014

Adams/Car RideGSE Damper

78

2. Rather creating a new model, use the example found in the Adams/Car Ride shared database (<aride_shared>/gse_dampers.tbl/damper_example_tf.mdl). To open damper_example_tf.mdl, from the File menu, select Open. Or, double-click the file in the file browser.

In the following context, the damper control system will be used as the example to illustrate the process. Following figure shows the damper Simulink model provided and its associated plant input and outputs.

Step Six -Code Generation of Simulink Damper Model (Control System)

First you will configure MATLAB/Real-Time Workshop and then you will create the External System Library from the Simulink model. Given a controller designed with the appropriately designated inports and outports, the following steps are required to export the model using RTW.

1. From the Tools menu, point to Real-Time Workshop, and then select Options.

The Simulation Parameters dialog box appears.

2. Verify Generate code only option is not selected.

3. Select Browse next to System target file and choose the rsim.tlc target.

The completed Simulink Parameters dialog box should look as shown below.

Page 45: Car Ride 2014

79Working with ComponentsGSE Damper

4. From the treeview on the left side of the window, select Solver.

The dialog box displays the Solver options as shown below

Page 46: Car Ride 2014

Adams/Car RideGSE Damper

80

5. Set Solver options Type to Variable-Step. (If selecting Fixed-Step solver, set Mode to SingleTasking.)

6. Under zero-crossing options, set Zero-crossing to Disable All.

The completed Simulink Parameters dialog box should look as shown below.

7. From the treeview on the left side of the window, select Optimization.

The dialog box displays the Advanced options as shown in below figure.

Page 47: Car Ride 2014

81Working with ComponentsGSE Damper

8. Verify Inline parameters options is selected. Enabling Inline parameters has the following effects:

• Real-Time Workshop uses the numerical values of model parameters, instead of their symbolic names, in generated code.

• Reduces global RAM usage, because parameters are not declared in the global parameters structure.

9. Select "Configure…" button to open the Model Parameters Configuration dialog box and verify that parameters ReboundDamping and CompressionDamping are selected as Global (tunable) parameters. This will allow Adams to create design variables for these parameters.

Page 48: Car Ride 2014

Adams/Car RideGSE Damper

82

10. Select OK to close the Model Parameters Configuration dialog box.

Page 49: Car Ride 2014

83Working with ComponentsGSE Damper

11. Click Apply.

12. Define the parameters in MATLAB workspace by issuing the following

ReboundDamping = 100;

CompressionDamping = 200;

(You can access the two MATLAB variables from the Simulink model by double-clicking them.)

Page 50: Car Ride 2014

Adams/Car RideGSE Damper

84

13. Select the Real-Time Workshop tab

14. To begin code generation and build the RTW library, select Build

Page 51: Car Ride 2014

85Working with ComponentsGSE Damper

Messages will appear in the MATLAB command window indicating successful code generation and RTW library creation. You should see messages that end with the following:

Creating library ..\damper_example_tf.lib and object ..\damper_example_tf.exp "### Created Adams External System Library damper_example_tf.dll" E:\tmp\gse_damper\damper_example_tf_rsim_rtw>exit /B 0 ### Successful completion of Real-Time Workshop build procedure for model: damper_example_tf

The library you created will be in your working directory.

Step Seven - Select the Damper Library and Simulate

First you will start Adams/Car and open component test rig, and then simulate your Adams model containing the GSE for the control system.

To start Adams/Car and import External System Library (ESL):

1. If you haven't already done then launch Adams/Car

2. Load the Adams/Car Ride plug-in, if not already loaded and open the assembly: component_damper_example.asy

3. Use Replace feature in Aride to replace Damper with GSE_damper

(Right click the assembly and select Damper:component_damper_001.das_dar_ride_damper -> Replace)

Page 52: Car Ride 2014

Adams/Car RideGSE Damper

86

4. Click OK. This will launch the Modify GSE Damper dialog box. If not, Right Click Damper: component_damper_001.das_dar_ride_damper and select Modify

5. Click the to import the External System Library (ESL) for the damper. This will launch a GSE Damper Code Import dialog box.

6. Right-click the Library to be imported field, and select Browse. Choose damper_example_tf.[dll,so]

7. Click the Property file name field and enter "damper_example_tf"

This will create a properly file for the ESL and will automatically update the Property File filed of Modify GSE Damper dialog to point it.

To run simulation and plot GSE_damper force:

1. From the Ride menu, point to Component Analysis, and then select Component-Model Test Rig …

The Adams/Car Ride Component Analysis dialog box appears.

(Please refer Aride Component Analysis help to do Component Analysis.)

Page 53: Car Ride 2014

87Working with ComponentsGSE Damper

2. Plot the force from GSE damper force in Adams/Post Processor

Page 54: Car Ride 2014

Adams/Car RideHydromounts

88

Hydromounts

Component Name

ac_hydro_bushing

Source Directory

/$MDI_RIDE_PLUGIN/template_builder/udes/hydro_bushing

Description

This component is based on the Weber model, which consists of a hydro path, a parallel spring, and a parallel damper.

Nonlinear Model

The nonlinear model consists of up to eight parameters:

• CouplingStiffness

• RubberStiffness

• LinearFluidDamping

• RubberDamping

• EffectiveFluidMass

• CouplingStiffnessDeclining

• QuadraticFluidDamping

• Clearance

Specifications

.ARIDE.parts.ac_hydro_bushing

Parameters

Parameter: Type: Function:

property_file string variable name of property file

bushing_property_file string variable name of the bushing property file

super_impose_bushing integer variable togggle if the spline from the original bushing property file will be superimposed in the direction of the hydro component

hydro_coordinate string variable hydro direction coordinate

t_preload_x real variable translational preload

Page 55: Car Ride 2014

89Working with ComponentsHydromounts

Input Parameters

Output Parameters

none

Objects

t_preload_y real variable translational preload

t_preload_z real variable translational preload

r_preload_x real variable rotational preload

r_preload_y real variable rotational preload

r_preload_z real variable rotational preload

t_offset_x real variable translational offset

t_offset_y real variable translational offset

t_offset_z real variable translational offset

r_offset_x real variable rotational offset

r_offset_y real variable rotational offset

r_offset_z real variable rotational offset

i_geoMarker Marker geometry ref marker

j_geoMarker marker geometry ref marker

geoRadius real variable geometry radius

geoLength real variable geometry length

Input parameter: Type: Function:

i_marker object variable action marker

j_marker object variable marker whose parent is the reaction part and reference marker

Object: Type: Function:

data_array Adams array array to pass the scaling factors and preloads to the field subroutine

fx_spline Adams spline force spline set to 0, depent on Hydro_Direction

fy_spline Adams spline set to 0, depend on Hydro_Direction

fz_spline Adams spline set to 0, depend on Hydro_Direction

Parameter: Type: Function:

Page 56: Car Ride 2014

Adams/Car RideHydromounts

90

tx_spline Adams spline torque spline

ty_spline Adams spline

tz_spline Adams spline

hydro_test_data_cdyn Adams spline stiffness

hydro_test_data_phase Adams spline angle

hydro_identification_data_cdyn Adams spline stiffness

hydro_identification_data_phase

Adams spline angel

i_graphic revolution graphics on I part

j_graphic cylinder graphic on J part

disp_request request displacement request

velo_request request velocity request

force_request request force request

output_request request hydroForce, Fluidvelocity, Fluiddisplacement

field field standard bushing field subroutine (900)

hydro_force_i sforce force representing the hydro path in z direction (action only)

hydro_force_j sforce hydro_force_i

hydro_disp state variable displacement difference between force marker and channel fluid displacement including clearance

hyrdo_diff_channel_disp diff displacement state of fluid in channel

hydro_Direction string acting direction of hyrdo force: values : 'x' | 'y' | 'z'

hydro_DirectionMarker marker direction for hydro_force_i and _j

hydro_RubberStiffnes real_variable units: translational stiffness [N/mm]

hydro_RubberDamping real_variable units: translational damping [Ns/mm]

hydro_CouplingStiffness real_variable units: translational stiffness [N/mm]

hydro_LinearFluidDamping real_variable units: translational damping [Ns/mm]

hydro_QuadraticFluidDamping real_variable units: translational damping [Ns²/mm²]

hydro_CouplingStiffnessDeclining

real_variable units: [1/mm²]

hydro_EffectiveFluidMass real_variable units: [kg]

hyrdo_Clearance real_variable units: [mm]

Object: Type: Function:

Page 57: Car Ride 2014

91Working with ComponentsHydromounts

Request Definition

disp_request

user (905,1,i_marker,j_marker,field)

velo_request

user (905,2,i_marker,j_marker,field)

force_request

user (905,3,i_marker,j_marker,field)

Component name: Component units: Definition:

dx length x-distance between i_marker and j_marker

dy length y-distance between i_marker and j_marker

dz length z-distance between i_marker and j_marker

dm length magnitude

ax angle angle about x

ay angle angle about y

az angle angle about z

amag angle magnitude

Component name: Component units: Definition:

vx velocity x-velocity between i_marker and j_marker

vy velocity y-velocity between i_marker and j_marker

vz velocity z-velocity between i_marker and j_marker

vm velocity magnitude

wx angular_velocity

wy angular_velocity

wz angular_velocity

wm angular_velocity magnitude

Component name: Component units: Definition:

bushing_fx force x-force between i_marker and j_marker

bushing_fy force y-force between i_marker and j_marker

Page 58: Car Ride 2014

Adams/Car RideHydromounts

92

output_request

Subsystem Parameters

Design Parameters

bushing_fz force z-force between i_marker and j_marker

fm force magnitude

bushing_tx torque

bushing_ty torque

bushing_tz torque

tm torque magnitude

Component:Component

name:Component

units: Definition:

f2 hydroForce force force on i-marker of sforce hydro_force_i

f3 Fluidvelocity velocity state of hydro_diff_channel_velo

f4 Fluiddisplacement displacement state of hydro_diff_channel_disp

Top level: Sub level:

property_file

t_preload_(x-z)

r_preload_(x-z)

t_offset_(x-z)

r_offset_(x-z)

Parameter: Type: Function:

fx_scaling_factor real variable scaling factor (DOE)

fy_scaling_factor real variable scaling factor (DOE)

fz_scaling_factor real variable scaling factor (DOE)

tx_scaling_factor real variable scaling factor (DOE)

ty_scaling_factor real variable scaling factor (DOE)

tz_scaling_factor real variable scaling factor (DOE)

Hydro_RubberStiffnes_scaling_factor real_variable scaling factor (DOE)

Hydro_RubberDamping_scaling_factor real_variable scaling factor (DOE)

Component name: Component units: Definition:

Page 59: Car Ride 2014

93Working with ComponentsHydromounts

Macros

Create Macro: (call: acar template_builder instance ac_hydro_bushing create) Adams/Car Ride executes this macro when you create an instance of the definition ac_hydro_bushing.

Modify Macro: (call: acar template_builder instance ac_hydro_bushing modify) Adams/Car Ride executes this macro when you modify an instance of the definition ac_hydro_bushing.

Delete Macro: (call: acar template_builder instance ac_hydro_bushing delete) This macro deletes all the entities which have been created exclusively for the instance.

About Input Hydromount Property FilesThe block [MDI_HEADER] must be exactly the same as in the example input hydromount property file.

In the block [UNITS] you could modify LENGTH to be either m or mm.

The block [GENERAL] must contain all parameters listed in the sample file.

• The DEFINITION is always '.ride.attachment.ac_hydro_bushing'.

• The HYDRO_COORDINATE can be x, y or z. This parameter determines the acting direction of the hydro force with respect to the ac_hydro_bushing reference system.

• The BUSHING_PROPERTY_FILE is a standard ac_bushing property file that defines all six stiffness and damping components of a bushing.

• The SUPER_IMPOSE_BUSHING parameter can be set to:

• Off - The bushing component with the same direction as the hydro force component is set to zero.

• On - The bushing component is superimposed. The superimpose option is useful because it lets you add an impact stiffness to the hydro force component. During the identification process, the bushing stiffness and damping coefficients are not considered.

• The block [HYDRO_TEST_DATA] contains four columns of data. These are the measured data of the hydromount. For every amplitude you must have the same frequencies. The number of amplitudes is not fixed. You could also use a property file including the hydro parameters, which you can edit manually, or use a file that was written by a previous identification process. This

Hydro_CouplingStiffness_scaling_factor real_variable scaling factor (DOE)

Hydro_LinearFluidDamping_scaling_factor real_variable scaling factor (DOE)

Hydro_QuadraticFluidDamping_scaling_factor real_variable scaling factor (DOE)

Hydro_CouplingStiffnessDeclining_scaling_factor real_variable scaling factor (DOE)

Hydro_EffectiveFluidMass_scaling_factor real_variable scaling factor (DOE)

Hydro_Clearance_scaling_factor real_variable scaling factor (DOE)

Parameter: Type: Function:

Page 60: Car Ride 2014

Adams/Car RideHydromounts

94

allows you to first use rather larger error tolerances to speed up the process with relatively rough results before you run the identification process using those results as initial values with a smaller error tolerance. Or you could add additional test data later and redo the identification based on previously identified parameters.

Example Input Hydromount Property FileThe following is a sample input hydromount property file (extension .hbu). This sample file contains the minimum set of required data.

Learn about input hydromount property files.

$-----------------------------------------------------------MDI_HEADER[MDI_HEADER] FILE_TYPE = 'hbu' FILE_VERSION = 1.0 FILE_FORMAT = 'ASCII'$----------------------------------------------------------------UNITS [UNITS] LENGTH = 'mm' FORCE = 'newton' ANGLE = 'degrees' MASS = 'kg' TIME = 'second' $--------------------------------------------------------------GENERAL [GENERAL] DEFINITION = '.ride.attachment.ac_hydro_bushing' HYDRO_COORDINATE = 'z' BUSHING_PROPERTY_FILE = '<ride>/bushings.tbl/mdi_0001.bus' SUPER_IMPOSE_BUSHING = 'off' $------------------------------------------------------HYDRO_TEST_DATA [HYDRO_TEST_DATA]

{amplitude frequency cdyn phase}

0.100000 5.000000 620.0 7.7

0.100000 8.000000 652.0 16.2

0.100000 10.000000 776.0 20.4

0.100000 12.000000 911.0 20.2

0.100000 15.000000 1038.0 12.9

0.100000 20.000000 963.0 5.5

0.100000 25.000000 902.0 4.0

0.100000 30.000000 881.0 4.3

0.100000 40.000000 841.0 5.3

Page 61: Car Ride 2014

95Working with ComponentsHydromounts

Example Output Hydromount Property File The following is an example output hydromount property file. We left out the data for frequencies 4 - 39 Hz.

$-----------------------------------------------------MDI_HEADER [MDI_HEADER] FILE_TYPE = 'hbu' FILE_VERSION = 1.0 FILE_FORMAT = 'ASCII' $-----------------------------------------------------UNITS [UNITS] LENGTH = 'mm' FORCE = 'newton' ANGLE = 'degrees' MASS = 'kg' TIME = 'second' $-----------------------------------------------------GENERAL [GENERAL] DEFINITION = '.ride.attachment.ac_hydro_bushing' HYDRO_COORDINATE = 'z' BUSHING_PROPERTY_FILE = '<ride>/bushings.tbl/mdi_0001.bus' SUPER_IMPOSE_BUSHING = 'off' $-----------------------------------------------------HYDRO_PARAMETERS [HYDRO_PARAMETERS] RUBBER_STIFFNESS = 406.544598 RUBBER_DAMPING = 0.29298822 COUPLING_STIFFNESS = 282.526692 COUPLING_STIFFNESS_DECLINING = 0.071232 LINEAR_FLUID_DAMPING = 1.10642663 QUADRATIC_FLUID_DAMPING = 0.01834762 EFFECTIVE_FLUID_MASS = 51.416425 CLEARANCE = 0.0

0.100000 50.000000v 838.0 6.6

0.800000 5.000000 620.0 9.9

0.800000 8.000000 620.0 20.9

0.800000 10.000000 691.0 29.1

0.800000 12.000000 855.0 32.4

0.800000 15.000000 1085.0 25.2

0.800000 20.000000 1142.0 12.0

0.800000 25.000000 1100.0 7.0

0.800000 30.000000 1068.0 5.4

0.800000 40.000000 1020.0 5.3

0.800000 50.000000 1031.0 5.6

{amplitude frequency cdyn phase}

Page 62: Car Ride 2014

Adams/Car RideHydromounts

96

$-----------------------------------------------------HYDRO_IDENTIFICATION_DATA[HYDRO_IDENTIFICATION_DATA]

$-----------------------------------------------------HYDRO_TEST_DATA [HYDRO_TEST_DATA]

{amplitude frequency cdyn phase}

0.100000 1.000000 404.863819 1.243071

0.100000 2.000000 399.691551 2.618614

0.100000 3.000000 388.455029 4.605679

... continue

0.100000 40.000000 713.285910 6.099968

0.500000 1.000000 404.772004 1.302907

0.500000 2.000000 399.309176 2.830528

0.500000 3.000000 389.903747 4.774778

... continue

0.500000 40.000000 716.810500 6.126563

1.000000 1.000000 404.777324 1.347649

1.000000 2.000000 399.296585 3.024592

1.000000 3.000000 390.207932 5.272207

... continue

1.000000 40.000000 700.288389 6.281555

{amplitude frequency cdyn phase}

0.100000 1.000000 392.000000 1.900000

0.100000 2.000000 393.000000 3.800000

0.100000 3.000000 393.000000 4.800000

... continue

0.100000 40.000000 773.000000 4.700000

0.500000 1.000000 389.000000 2.800000

0.500000 2.000000 386.000000 4.100000

0.500000 3.000000 385.000000 5.800000

... continue

0.500000 40.000000 734.000000 4.800000

1.000000 1.000000 379.000000 3.100000

Page 63: Car Ride 2014

97Working with ComponentsHydromounts

$OBJECTIVE_FUNCTION = 1.5051 $INTEGRATOR_ERROR = 0.0050 $STEADY_STATE_ERROR = 0.0100 $CONVERGENCE_TOLERANCE = 0.0050 $*** OPTIMIZATION ABORTED ***

1.000000 2.000000 377.000000 4.800000

1.000000 3.000000 378.000000 6.900000

... continue

1.000000 40.000000 700.000000 4.700000

{amplitude frequency cdyn phase}

Page 64: Car Ride 2014

Adams/Car RideHydromounts

98

Page 65: Car Ride 2014

Tools

Page 66: Car Ride 2014

Adams/Car RideHydromount-Parameter Identification Tool

100

Hydromount-Parameter Identification Tool You can use this tool to identify the parameters of a hydromount model for given measurements of dynamic stiffness and loss angle dependent on frequency. The model used for the identification is identical to the model included in Adams. The output of the identification process is a property file that contains all the parameters of the Adams element.

If the start conditions have not been defined through manual input or through the property file, the identification routine starts with a linear model of the hydromount to determine the proper start conditions for the nonlinear model.

Learn more about the hydromount-parameter identification tool:

• About Hydromount Models

• Identification Process

• Identifying Hydromount Parameters

• Calculate Frequency Response

About Hydromount Models

You can use two kinds of hydromount models:

• Linear models - Consist of five parameters and do not include the clearance, quadratic fluid damping, and coupling stiffness declining terms, which are included in the complete nonlinear model.

• Coupling Stiffness

• Rubber Stiffness

• Linear Fluid Damping

• Rubber Damping

• Effective Fluid Mass

• Nonlinear models - Consist of up to eight parameters. The additional parameters to the linear model are:

• Coupling Stiffness Declining

• Quadratic Fluid Damping

• Clearance

Page 67: Car Ride 2014

101ToolsHydromount-Parameter Identification Tool

Mk Effective_Fluid_Mass←

xΔ Displacement(i_mar,j_mar,j_mar) - dz0←x·Δ Velocity(i_mar,j_mar,j_mar)←

x1 Displacement(Mk)←

v1 Velocity(Mk)←

Kquad Coupling_Stiffness_Declining←

Kb Linear_Coupling_Stiffness←

Dk Linear_Fluid_Damping←

Dk_quad Quadratic_Fluid_Damping←

Kt Rubber_Stiffness←

Ct Rubber_Damping←

Coupling_Stiffness_Displacement_ xΔ :

xΔxΔ clearance+ xΔ clearance+ 0<( )& xΔ 0<( )⇐xΔ clearance– xΔ clearance– 0>( )& xΔ 0>( )⇐

0;else

=

Nonlinear_Coupling_Stiffness_Factor_q:

q

1 Kquad* xΔ * xΔ–( ) Kquad 0<( )⇐

1 Kquad 0=( )⇐

1 1 Kquad* xΔ * xΔ+( )⁄ Kquad 0>( )⇐

=

Nonlinear_Fluid_Damping_Factor_c:

c Dk Dk_quad* v1+=

Coupling_Force:

Fcoupl x1 xΔ–( )*Kb*q=

Differential_Equation_Fluid_Mass:

v1·

1– Mk⁄ * v1*c Fcoupl+( )=

x1·

v1=

Page 68: Car Ride 2014

Adams/Car RideHydromount-Parameter Identification Tool

102

hydro_force Kt– * xΔ Ct– * x·Δ Fcoupl+=

Page 69: Car Ride 2014

103ToolsHydromount-Parameter Identification Tool

Note: The model is valid up to 100 Hz, depending on the quality of the input data. The frequency range of the input data should start below the first eigen frequency of the hydromount. The data supplied must be consistent. That is, for the first amplitude range there has to be a range of frequencies, for the next amplitude range the frequencies must be the same as the first amplitude range, and there must be the same number of rows of data, and so on. For example:

amplitude frequency

0.1 5

0.1 10

0.1 15

0.2 5

0.2 10

0.2 15

Page 70: Car Ride 2014

Adams/Car RideHydromount-Parameter Identification Tool

104

Identification Process The identification tool has three start conditions that determine the identification process:

• Without any Initial Parameters - All seven input parameters are zero.

• With Five initial Parameters - Five parameters are nonzero and the two nonlinear parameters are zero.

• With Seven initial Parameters - All seven input parameters are nonzero.

Identification Without any Initial Parameters

All input parameters in the interface are zero. Adams/Car Ride automatically sets all parameters to zero after loading a property file without the block [HYDRO_PARAMETERS]. After you select Go, the process uses the linear model to identify the following five parameters:

• Rubber stiffness

• Rubber damping

• Coupling stiffness

• Linear fluid damping

• Effective fluid mass

The parameters are initial values for the complete model. The process continues with an initial guess of the nonlinear parameters: quadratic fluid damping and coupling stiffness declining, to fit the nonlinear behavior of the hydro force. The clearance remains at zero. At this point, you can stop the optimizer and modify any parameter. To check frequency response, select Calculate Frequency Response. You can repeat the process at any time.

Identification With Five Initial Parameters

You can enter the hydro parameters in the dialog box, or have them load from the property file (if it contains a block [HYDRO_PARAMETERS]). In this case, the process also starts based on the linear model and continues with the nonlinear model as described in the identification process without any initial parameters.

Identification With Seven Initial Parameters

You can enter the hydro parameters in the dialog box, or have them load from the property file (if it contains a block [HYDRO_PARAMETERS]). In this case, the process directly uses the complete nonlinear model. In this final part of the identification process, all seven parameters are varied and only the clearance remains fixed.

Page 71: Car Ride 2014

105ToolsHydromount-Parameter Identification Tool

Identifying Hydromount Parameters

To identify hydromount parameters:

1. Load Adams/Car Ride plugin in Tools → Plugin Manager, if it is not already loaded. The "Ride" menu should appear as rightmost entry in Adams/Car upper menus.

2. Go to Ride → Tools → Hydromount-Parameter Identification.

3. Press F1 and then follow the instructions in the dialog box help for Hydromount-Parameter Identification.

4. Select Go.

Calculate Frequency ResponseAfter each iteration step, Adams/Car Ride automatically calculates the frequency response and updates the plots and parameters. You can manually modify each input parameter and calculate their frequency response.

Page 72: Car Ride 2014

Adams/Car RideIsolator-Parameter Identification Tool (IPIT)

106

Isolator-Parameter Identification Tool (IPIT)The Isolator-Parameter Identification Tool (IPIT) has been developed to identify the parameters of the single direction nonlinear frequency and amplitude dependent bushing model out of rubber bushing dynamic measuring data. The model used for the identification in IPIT is identical to the general bushing model included in Adams/Ride. The output of the identification process is a property file that contains all the parameters of the Adams element.

Learn more about the IPIT:

• IPIT GUI

• Bushing Model

• Bushing Measurement Data

• IPIT Optimizers

• Identification Process

• Running IPIT in batch mode

• Using with Adams/Chassis

• Running IPIT with bushing in 'g'-direction

• Modify the bushing template file

IPIT GUIFor starting the IPIT in Adams/ Car Ride:

Select: Ride → Tools → Isolator-Parameter Identification. This will open the IPIT GUI as shown below.

Page 73: Car Ride 2014

107ToolsIsolator-Parameter Identification Tool (IPIT)

Page 74: Car Ride 2014

Adams/Car RideIsolator-Parameter Identification Tool (IPIT)

108

With the top toolbar the user can Load or Save a .gbu bushing property file. Additionally there is quick access to the online help for IPIT and finally the option to Export the bushing CMD file. This option can be used to create a user defined strategy by editing the file and run the IPIT in batch mode with Adams/View. For more information about running the IPIT, please refer the section Running IPIT in batch mode.

The GUI it is structured in 3 main panels, the first at the top left contains, organized in a tab for each direction, all the bushing parameters. The tab will be set in the direction mentioned in the bushing property file under the keyword BUSHING_COORDINATE (= x/y/z/ax/ay/az/g). The x- to az-directions allows the user to fit the parameters for the general bushing using the 'Bouc-wen hysteresis model as described below. The 'g'- direction provides the IPIT fitting capabilities for the hydromount bushing or any other bushing defined in the bushing template file. The bottom left contains all the governing parameters referring to the identification process. On the right side there is the plot field, which displays the frequency response of the model; the dynamic stiffness in the plot is named Cdyn and the loss angle in the plot is named Phase. Finally there is a second tab, the Data, which displays the input file and the tabulated frequency response data. At the bottom of the GUI, there is the progress bar and below that there is the status bar which lists some useful information about current status of the IPIT such as the objective function during the identification process.

The figure below illustrates the three tabs which contains all the governing parameters referring to the identification process.

Page 75: Car Ride 2014

109ToolsIsolator-Parameter Identification Tool (IPIT)

Below follows the tabulated list of all the available options including the description and the default values.

Table 1 Error Control

Option Definition and default value

User Pars Supplying the MSCADS optimizer user parameters to tune MSCADS for the problem, refer to the related paragraph.

Default: 0,3,2

Convergence Tolerance Supplying the tolerance for which the objective function is considered converged.

Default:1*10-5

Max Function Evaluations

Supplying the maximum function evaluations allowed to the optimizer.

Default: 2000

Max Cycles The maximum cycles and frequency that governs the simulation end time. The simulation end time is reduced significant when the Sensor is enabled.

Default: 30

Integrator Error Specifies the Adams/Solver integration error.

Default: 1*10-3

Objective Ratio Phase/CDyn

Specifies the objective ratio between Loss Angle and dynamic stiffness. For rising the accuracy on dynamic stiffness fit this ratio can be increased to 4, 6 or in some cases up to 10.

Default: 2.0.

Table 2 Solver Control

Option Definition and default value

Optimizer Selects the optimizer method for the identification process, refer to the related paragraph.

Default: MINPACK.

Solver Choice Selects between the two available solvers Fortran and C++.

Default: Fortran.

Page 76: Car Ride 2014

Adams/Car RideIsolator-Parameter Identification Tool (IPIT)

110

Keep Files The Adams/Solver related files are not deleted when set to Yes.

Default: Yes

Sensor Activates or deactivates the Energy Sensor. When the sensor is activated the frequency response is captured during the time simulations of the bushing model and the simulation is terminated as soon the model has a stable response.

Default: Activated

Method Selects the method to calculate the frequency response (dynamic stiffness and loss angle).

Default: MinMax

Testrig Simulations Chooses to run the Adams simulation in parallel or in sequential mode. This option can reduce the computational time significantly.

Default: Parallel

Table 3 Strategy Control

Option Definition and default value

Run 3 steps strategy If set to 'yes', the IPIT uses the built-in strategy to identify the parameters of the bushing model for the supplied measuring data.

Stop after step Forces the IPIT to stop after finishing a certain step of the 3 steps strategy.

Table 4 Buttons

Option Definition and default value

Calculate Frequency Response

After each iteration step, IPIT automatically calculates the frequency response and updates the plots and parameters. By using this button user can plot the model response after each manual modification of the input parameters.

Go Selects to start the identification process.

Stop Selects to terminate the identification process. Note that the IPIT will not terminate immediately, but will finish the Adams simulations so that last data can be saved.

Table 2 Solver Control

Option Definition and default value

Page 77: Car Ride 2014

111ToolsIsolator-Parameter Identification Tool (IPIT)

Bushing ModelThe General Bushing model consists of three basic parts that have been positioned parallel, a non linear spring, a Bouc-Wen element and one transfer function; the mathematical model shown below:

IPIT is used for the identification of the parameters of the Bouc-Wen and the numerator and denominator coefficients of the TFSISO element out of given measurement data.

Static Spline (Non-linear spring)

The non-linear spring is dedicated to capture the non-linear effects that appear at the large deflection amplitudes caused by the non-uniform shape of the bushing. In general the gradient at small and medium amplitudes is linear and therefore has a small influence on the amplitude dependency in this range. In addition, this element is used for introducing a preload force on the bushing.

The data of the static spline is not calculated in the parameter identification process, but is a required input. The data should be the result of a low frequency and high amplitude test. In other words, the user has to supply the backbone of the quasi-static test curve of the bushing.

TFSISO numerator and denominator coefficients

This part is dedicated to describe the frequency dependency of rubber bushings in terms of dynamic stiffness and loss angle. The impedance transfer function is used in the default template. See TFSISO section for more information.

Bouc-Wen hysteresis model

The Bouc-Wen hysteresis element is used to model the amplitude dependency at 'small' amplitudes of the excitation. In IPIT there are three versions of the hysteresis model: the coupled, the uncoupled and the revised version.

In all the Bouc-Wen versions, the hysteretic non-dimensional displacement, z, is described by the following non-linear differential equation, with zero initial condition, z(0)=0:

Page 78: Car Ride 2014

Adams/Car RideIsolator-Parameter Identification Tool (IPIT)

112

where:

• a is the parameter controlling hysteresis amplitude

• β, γ, n are the three parameters controlling hysteresis shape

Uncoupled version [coup=0]

where:

• Alpha is the rigidity ratio

• ζ is the linear elastic viscous damping ratio

• ωn is the pseudo-natural frequency of the system

• k is the linear force scale

Coupled version [coup=1]

where:

• Alpha is the rigidity ratio

• ζ is the linear elastic viscous damping ratio

• ωn is the pseudo-natural frequency of the system

Revised version [coup=2]

where:

• Alpha is the linear Bouc-Wen force scale

• k is linear force scale

• Note that ωn and ζ are not used in this version

The coup = 2 is available since Adams 2013 release. If you want to use a .gbu property file with coup = 2 prior to that release, change the following in the .gbu file:

BUSHING_COUPLING = 0X_OMEGA = 1 (similar to Y, Z, AX, AY and AZ_OMEGA)X_ZETA = 0 (similar to Y, Z, AX, AY and AZ_ZETA)

z· t( ) γ x· t( ) z t( ) n 1–( )z t( )– βx· t( ) z t( ) n

– ax· t( )+=

f t( ) 2ζωnx· t( ) k ωn2x t( ) Alpha ωn

2z t( )+ +=

f t( ) 2ζωnx· t( ) Alpha ωn2x t( ) 1 Alpha–( ) ωn

2z t( )+ +=

f t( ) k x t( ) Alpha z t( )+=

Page 79: Car Ride 2014

113ToolsIsolator-Parameter Identification Tool (IPIT)

Bushing Measurement DataThe mathematical model has 6 parameters which are related to the amplitude dependency and 5 to 7 related to the frequency dependency. Taking into account that one measured point (frequency and amplitude) supplies two values, dynamic stiffness and loss angle, it is obvious that at least 3 measured amplitudes and 4 measured frequencies (for each measured amplitude) are required to achieve an exact mathematical solution.

Static Spline

The backbone of the quasi-static test loop of a bushing is used for determining the non-linear spline data. The measured (deflection) range should cover the operation range of the bushing (sometimes more than 8 mm). The measurements have to be performed including the preload.

Dynamic Data

The inputs of the model are amplitude and frequency while the outputs are dynamic stiffness and loss angle. The measured points, in frequency and amplitude range, of dynamic stiffness and loss are limited up to 128 points.

The data supplied must be in a squared matrix format. The number of frequency points of each amplitude should be identical. For example:

It is suggested to use the smallest possible number of points which can describe both amplitude and frequency response sufficiently for minimizing the computation time.

IPIT OptimizersIPIT supports two optimizers.

• MINPACK (default)

• MSCADS

Amplitude Frequency

0.1 5

0.1 10

0.1 15

0.2 5

0.2 10

0.2 15

Page 80: Car Ride 2014

Adams/Car RideIsolator-Parameter Identification Tool (IPIT)

114

1. MINPACK (default)

MINPACK aims for minimizing the sum of the squares of m nonlinear functions in n variables by the Levenberg-Marquardt algorithm. MINPACK uses an external file <adams_installation_directory>/aride/ shared_ride_database.cdb/general_bushing.tbl/ipit_par_constraints.txt which supplies the parameters constraints for each different identification step. These constraints can be modified by the user to achieve better results. For more information on the constraints file manipulation, please refer to the Tutorial for fitting Adams/Ride General Bushing parameters with IPIT (ref: KB8020826) available in the SimCompanion database.

2. MSCADS

MSCADS is a general purpose optimization program which can solve a variety of non-linear constrained and unconstrained optimization problems. The user can tune the MSCADS for their models by passing user parameters to MSCADS through the User pars option. In IPIT the MSCADS is limited to use unconstraint optimizer methods only. The above mentioned external file ipit_par_constraints.txt is not used by MSCADS, but by MINPACKonly.

Identification Process The Adams/Car Ride Isolator Parameter Identification Tool (IPIT) allows you to identify parameters of the general bushing, model out of measurement data. It should be noted that you can identify bushing parameters for one direction at a time only. To identify the bushing parameters for more directions, you can run the optimizer multiple times. The resulting bushing property file .gbu can be used in for instance Adams/Car for further study.

Following steps explain how to identify bushing parameters using the IPIT:

• Step one: Prepare the .gbu property file for use with the IPIT

• Step two: Set-up the IPIT for the bushing parameter identification process

Step one: Prepare the .gbu property file for use with the IPIT

To avoid confusion with the .gbu files, any general bushing can be used in Adams/Car Assembly to calculate the bushing force and behavior but can also be used in IPIT for parameter identification of the bushing parameters out of measurement data. The headings marked below with (**) are used in IPIT during the identification only and the headings marked with (*) are intended to be used in Adams/Car Ride when simulating the bushing force and response.

It should be noted that the IPIT identifies the bushing parameters for one direction at a time only as specified in the GBU file.

The following shows all the parameters that must be defined in the GBU property file:

[MDI_HEADER]

• Specify the type, version and the format of the property file.

Page 81: Car Ride 2014

115ToolsIsolator-Parameter Identification Tool (IPIT)

• Default: FILE_TYPE = 'gbu'FILE_VERSION = 2.0FILE_FORMAT = 'ASCII'

[UNITS]

• Specify the units of the test data under this block.

• Default: For IPIT the units are fixed to respectively:

LENGTH = 'millimeter'FORCE = 'newton'ANGLE = 'degrees'MASS = 'kilogram'TIME = 'second'

[GENERAL]

DEFINITION is always '.aride.attachment.ac_general_bushing'

BUSHING_COORDINATE(*) = x/y/z/ax/ay/az/g

• Choose one of the aforementioned coordinates for identification of the bushing.

BUSHING_SHAPE(**)=0/1/2/3

• Only the rectangular coupling is supported in IPIT.

• 0 or 1 is rectangular coupling, 2 is cylindrical coupling and 3 is spherical coupling

• Default: to '0', this field is optional for IPIT.

BUSHING_COUPLING=0/1/2

• There are three versions of Bouc-Wen hysteresis model: the coupled, uncoupled and revised version.

• For the coupled version select 0, for the uncoupled select 1 and for the revised version select 2.

• Default is '2', as the latest version of IPIT is developed for using this version.

• Not applicable for the g-direction.

[DAMPING]

• This field can be used to specify linear damping. It is suggested to use this parameter only when no Hysteresis (Bouc-Wen or TFSISO) model is used.

• There are 6 sets of damping parameters one for each coordinate (x/y/z/ax/ay/az).

• Default: '0.0', this block is optional.

[PRELOAD]

• This field can be used to modify the preload. It is suggested to modify the static spline instead of this parameter.

• There are 6 sets of preload parameters one for each coordinate (x/y/z/ax/ay/az).

Page 82: Car Ride 2014

Adams/Car RideIsolator-Parameter Identification Tool (IPIT)

116

• Default: '0.0', this block is optional.

[OFFSET]

• This field can be used to modify the offset of the static spline. It is suggested to modify the static spline instead of using this parameter.

• There are 6 sets of offset parameters one for each coordinate (x/y/z/ax/ay/az).

• Default: '0.0', this block is optional.

[SPLINE_SCALES]

• These scales are used by IPIT mainly as a switch to enable or disable the Static Spline component of the Bushing model. These can also be used in user defined strategies with the CMD export method.

• There are 6 sets of spline scale parameters one for each coordinate (x/y/z/ax/ay/az).

• Default: 1.0, so the Static Spline component of the Bushing model is enable. This block is compulsory.

[HYST_SCALES]

• These scales are used by IPIT as a switch to enable or to disable the Hysteresis / Bouc-Wen component of the Bushing model. These can also be used in user defined strategies with the CMD export method.

• There are 6 sets of spline scale parameters one for each coordinate (x/y/z/ax/ay/az).

• Default: 1.0, so the Hysteresis / Bouc-Wen component of the Bushing model is enable. This block is compulsory.

[TFSISO_SCALES]

• These scales are used by IPIT as a switch to enable or to disable the TFSISO component of the Bushing model. These can also be used in user defined strategies with the CMD export method.

• There are 6 sets of spline scale parameters one for each coordinate (x/y/z/ax/ay/az).

• Default: 1.0, so the TFSISO component of the Bushing model is enable. This block is compulsory.

[FX/ FY/ FZ/ TX/ TY/ TZ _CURVE]

• This block contains the Spline Curves data.

• There are 6 sets of Spline Curves parameters one for each coordinate (x/y/z/ax/ay/az).

• No default values and it is compulsory only for the identifying direction.

[BUSHING_PARAMETERS]

• This block is used to supply bushing parameters for Bouc-Wen and TFSISO. While using in Adams/Car Assembly and IPIT, the bushing force is calculated using these parameters. IPIT updates these data during the optimization process.

• There are 6 sets of bushing parameters one for each coordinate (x/y/z/ax/ay/az).

Page 83: Car Ride 2014

117ToolsIsolator-Parameter Identification Tool (IPIT)

• Default: (valid for the revised version of the Bouc-Wen model).

[BUSHING_TEST_DATA] (*)

• This block contains four columns of data, the dynamic measuring data of the bushing. As it is discussed in the Bushing Measurement Data section, all measured amplitudes should have the same number of measured frequencies.

• This block is compulsory for the operation of IPIT.

• Input format: the supplied matrix should have the following columns, always in this listed order:

{amplitude frequency cdyn phase}

[BUSHING_SCALE_DATA] (*)

• This block contains a matrix with exactly the same dimensions as the BUSHING_TEST_DATA block. These scales are used by IPIT to calculate the objective function during the '3 steps strategy' and also can be used in user defined strategies through the export CMD method. The common values of this matrix are 0 and 1, so this matrix is used to define which points of the measuring data are used to calculate the objective function.

• Default: 1.0.

• This is optional block, IPIT will pop up a message that it will use a default unity scale data if this is not supplied in the .gbu.

[BUSHING_IDENTIFICATION_DATA] (*)

• This block contains a matrix with exactly the same dimensions as the BUSHING_TEST_DATA block. These are the dynamic stiffness and phase data identified by the bushing model in the optimization process.

Parameter Default Value

Alpha It is suggested to put the average dynamic stiffness of all the measured amplitude range at the lowest frequency

Beta 1.7

Gamma 0.2

Zeta 0.0 - it is not used in the revised version of Bouc-Wen

Omega 0.0 - it is not used in the revised version of Bouc-Wen

a 1.0

n 0.2

K 0.0

Num [0.0,0.0]

Den [0.0,1.0]

Page 84: Car Ride 2014

Adams/Car RideIsolator-Parameter Identification Tool (IPIT)

118

• Default: This is an optional block. In general the dynamic stiffness and loss angle data is added by IPIT after each optimization process.

See Example Input Bushing Property File for Identification

See Example Input Bushing Property File for Identification - one direction

See Example Output Bushing Property File

It is suggested to use the Example Input Bushing Property File for Identification - one direction for identifying the parameters for one direction at the time. By using this property file users can replace the [BUSHING_TEST_DATA] and the STATIC SPLINE blocks with their data for each direction.

Step two: Set-up the IPIT for the bushing parameter identification process

After loading the prepared .gbu property file it is required to enter the initial value of the Alpha. Alpha can be derived from the average dynamic stiffness over the whole measured amplitude range of the points at the lowest frequency, by reading the plot. User could also edit manually the parameters to and try to find good starting values before you run the identification process.

Next is to set the optimization and solver options. There are various controls provided in the IPIT which helps the user to setup the IPIT for their specific needs. These controls are listed in the Error and Solver control tabs as presented in the IPIT GUI section.

Under the Strategy control tab one finds the built-in '3 steps strategy'. When this 3 steps strategy is activated, IPIT identifies the bushing parameters in following order:

a. During the first step the TFSISO numerator and denominator coefficients are identified. An external solver is used to do a fit in frequency domain using all test data points.

b. At the second step the Bouc-Wen model parameters are identified using a limited number of test data points, only data points at the lowest frequency.

c. Finally in the third step both Bouc-Wen and TFSISO parameters are identified using the parameters resulted from steps a and b as initial values.

Note: As already stated, there are 6 sets of parameters for each [BLOCK], one for each coordinate (x/y/z/ax/ay/az). The blocks [MDI_HEADER], [UNITS], [GENERAL] and the STATIC SPLINE for the specified BUSHING_COORDINATE direction on the block [GENERAL] are compulsory; the others are optional during the identification process in IPIT.

Note: Steps a and b are relatively fast and may already give acceptable fit-results. Step c will take most time as all parameters are identified using all test data. Please refer to the Tutorial for fitting Adams/Ride General Bushing parameters with IPIT (ref: KB8020826) available in the SimCompanion database.

Page 85: Car Ride 2014

119ToolsIsolator-Parameter Identification Tool (IPIT)

To activate the 3 steps fitting strategy set 'Run 3 steps strategy' to 'yes'. It is possible to terminate the optimization process after each intermediate step, by setting 'Stop after step' to '1' for terminating the

optimization after 1st step or '2' for the second or 'No stop' to let the optimization complete all three steps.

The identification process has to be executed multiple times, each time the parameters for one direction can be estimated. The user has to assembly a new .gbu property file which includes the parameters for each direction following the Example Bushing Property File. Finally this property can be used in for instance Adams/Car for further study.

Running IPIT in batch mode

Export Adams/View CMD file

The user can export an Adams/View CMD file to define his own fit-strategy using File → Export CMD. The cmd file can be run in batch mode as follows;

Windows: adams2014 acar ru-acar b abcd.cmd

Linux: adams2014 -c acar ru-acar b abcd.cmd

The CMD file can be modified to get a user defined optimization strategy. For more information, see the comments in the exported CMD file.

Creating custom IPIT strategy

IPIT supports custom user strategies through CMD language if you desire to use scales IPIT provides for default strategy. The sample CMD file is shown below for one such two step strategy.

!##################################################################################### ! echo off Default: command_file update_screen=off & echo_commands=off & on_error=ignore_command ! load plugin plugin load plugin_name = .MDI.plugins.aride ! batch IPIT commands variable set variable=.ARIDE.runPy int= (eval(RUN_PYTHON_CODE("import sys; import boucwenbushing; "))) variable set variable=.ARIDE.runPy int= (eval(RUN_PYTHON_CODE("boucwenbushing.PropertyFileName = \"C:/abcd/efg/private.cdb/general_bushing.tbl/xyz.gbu\" ")))variable set variable=.ARIDE.runPy int= (eval(RUN_PYTHON_CODE("boucwenbushing.RmFiles = 1"))) variable set variable=.ARIDE.runPy int= (eval(RUN_PYTHON_CODE("boucwenbushing.IsSensor = 1"))) variable set variable=.ARIDE.runPy int= (eval(RUN_PYTHON_CODE("boucwenbushing.ReqID = 112"))) variable set variable=.ARIDE.runPy int= (eval(RUN_PYTHON_CODE("boucwenbushing.Solver = \"F77\" "))) variable set variable=.ARIDE.runPy int= (eval(RUN_PYTHON_CODE("boucwenbushing.ConvergenceTolerance = 1e-3")))variable set variable=.ARIDE.runPy int= (eval(RUN_PYTHON_CODE("boucwenbushing.MaxFun = 20000"))) variable set variable=.ARIDE.runPy int= (eval(RUN_PYTHON_CODE("boucwenbushing.Cycles = 30"))) variable set variable=.ARIDE.runPy int= (eval(RUN_PYTHON_CODE("boucwenbushing.ADS_User = \"0,3,2\""))) variable set variable=.ARIDE.runPy int= (eval(RUN_PYTHON_CODE("boucwenbushing.stopProgram = \" RUN\""))) !######################################################################################!! To create user three step strategy !! 1) Comment out "batchrun_strategy" command above!! 2) Uncomment following commands, make use of "strategy_run_step" function to create stragey steps!! !! Example user strategy:!! 1) Step=1: Activate fit in frequency domain

!variable set variable=.ARIDE.runPy int= (eval(RUN_PYTHON_CODE("boucwenbushing.Optimizer().strategy_run_step(in_gbu = boucwenbushing.PropertyFileName, step = 1, is_bw = 1, run_bw = 1, is_tf = 1, run_tf = 1, fr_fit = 1, frq_index=0, amp_index=0, OptimizerRoutine = boucwenbushing.OptimizerRoutine)")))!! 2) Step=2: Activates Bouc-wen element in general bushing only, pick first frequency amplitudes as objective to fit

!variable set variable=.ARIDE.runPy int= (eval(RUN_PYTHON_CODE("boucwenbushing.Optimizer().strategy_run_step(in_gbu = boucwenbushing.PropertyFileName, step = 2, is_bw = 1, run_bw = 1, is_tf = 1, run_tf = 0, fr_fit = 0, frq_index=1, amp_index=0, OptimizerRoutine = boucwenbushing.OptimizerRoutine)")))

Page 86: Car Ride 2014

Adams/Car RideIsolator-Parameter Identification Tool (IPIT)

120

!! 3) Step=3: Activate both Bouc-wen and TFSISO elemets in general bushing, pick all frequencies and all amplitude curves as objective to fit

!variable set variable=.ARIDE.runPy int= (eval(RUN_PYTHON_CODE("boucwenbushing.Optimizer().strategy_run_step(in_gbu = boucwenbushing.PropertyFileName, step = 3, is_bw = 1, run_bw = 1, is_tf = 1, run_tf = 1, fr_fit = 0, frq_index=0, amp_index=0, OptimizerRoutine = boucwenbushing.OptimizerRoutine)")))

It should be noted that the user can choose scales that are designed for default steps in CMD mode, however the user can choose particular amplitude or frequency as required while creating custom CMD based strategy.

If the user want to design his strategy in more general sense with scales different from provided by IPIT in three step default strategy, it can be done in interactive mode as follows:

1. Create input.gbu file with proper scales under [BUSHING_SCALE_DATA], make sure you choose appropriate values for HYST_SCALES and TFSISO_SCALES.

2. After finishing the IPIT run, make sure that you have file: xyz_StrAfterStp_1.gbu in current working directory.

3. Edit this file to update scales under [BUSHING_SCALE_DATA], HYST_SCALES and TFSISO_SCALES

4. Rename it as original name or different name.

5. Read this updated file in IPIT and fire as new job.

6. Repeat process until your strategy ends. Each run in this process is your strategy step.

Using with Adams/ChassisThe Isolator-Parameter Identification Tool (IPIT) uses TeimOrbit property files. Since Adams/Chassis is only compatible with XML property files, the tool will allow you to read in XML formatted property files and to perform the required conversions. When saving the property file, IPIT will save the data into an XML bushing property file, which can be imported in the Adams/Chassis connector editor.

Running IPIT with bushing in 'g'-directionWhen loading the file <schared_ride_database>/general_bushing.tbl/gen_bus002.gbu, the IPIT will start up in the g-direction setting, see below:

Page 87: Car Ride 2014

121ToolsIsolator-Parameter Identification Tool (IPIT)

By default the bushing_template used for the g-direction is the hydromount bushing, as also used by the Hydromount Parameter Identification Tool. However the IPIT will run the optimization using Adams/Solver simulation with the bushing component testrig, while the Hydromount Parameter Identification Tools uses an internal solver.

Note that Strategy Control setting 'Run 3 steps strategy = Yes' will not work for the g-direction.

Page 88: Car Ride 2014

Adams/Car RideIsolator-Parameter Identification Tool (IPIT)

122

By changing the bushing_template (see below), the optimization of any bushing can be done with the IPIT as long as the number of parameters does not exceed 128.

Modify the bushing template fileThe IPIT uses a python template file to calculate the bushing response using Adams/Solver (C++ or F77). This python template file contains Adams/Solver .acf and .adm files. You can modify the Adams/Solver statements and add for instance your own user libraries for bushings in this template. The example python template file is located in: adams_install/python/Arch/Lib/site-packages/bushing_templates.py, where Arch is your platform (win32, linux32 and so on.) and install is your Adams installation folder. If you open the template file, you will find a number of template variables including description at the beginning of this file. You may study the example template to understand how the template variables are used to create a bushing model used in combination with the IPIT. Modification of the template file allows you to include your own bushing model. The IPIT uses two important python string variables acftext and admtext to recognize your ADM and ACF templates.

The example python template file has one .acf template and two .adm sample templates. The admtext python string variable lists the .adm template for the Adams/Car Ride general bushing which is used by the IPIT to identify the general bushing parameters (example template file for BUSHING_COORDINATE = 'x' or 'y' or 'z' or 'ax' or 'ay' or 'az' or 'g').

The python template file can contain multiple ACF and ADM templates, but the IPIT only uses the template represented by the python string variables acftext and admtext.

It is also possible to create a customized python template and hook-up it to the IPIT by defining environment variable IPIT_TEMPLATE_PATH. The user template file name is restricted to 'user_bushing_templates.py' and it should reside in the directory referred by environment variable IPIT_TEMPLATE_PATH (for example, IPIT_TEMPLATE_PATH=C:/users/IPIT_user_dir). If the path or file is not accessible or incorrect, IPIT uses the default template from the installation, which is the template for the Hydromount bushing. IPIT also informs the user about which template it is using by printing a message in the command shell.

Page 89: Car Ride 2014

123ToolsRoad-Profile Generation Tool

Road-Profile Generation ToolThe Adams/Car Ride tool for generating road profiles with roughness uses a mathematical model developed by Sayers [1, 2]. The model is empirical: it is based on the observed characteristics of many measured profiles of roads of various types. The model also provides for the synthesis of profiles for both the left and right wheeltracks.

Learn more about the road-profile generation tool:• About the Road-Profile Generation Tool

• Parameter Variables for Sayers Roughness Model

• Generating a Road Profile

• References

About the Road-Profile Generation Tool

For a single wheeltrack, the model assumes that the power-spectral density (PSD) of the displacement

(elevation) of a road profile, , is a function of wavenumber, , given by the equation:

: (1)

Therefore, it is assumed that roughness comes from three components. Each is obtained from an independent source of white noise, that is, random numbers.

• The first component, with amplitude , is white-noise elevation.

• The second, with amplitude , is white-noise slope (velocity) that is integrated once with

respect to time.

• The third, with amplitude , is white-noise acceleration that is integrated twice with respect to

time.

The letter above denotes Gaussian. Each sequence of random numbers is assumed to have a Gaussian

distribution with a mean value of zero and a standard deviation, , of:

: (2)

where:

• is a white-noise amplitude for one of the three terms in Equation 1 ( )

• is the interval between samples, expressed in the inverse units of those used for wavenumber

Gd ν

Gd v( ) Ge

Gs

2πν( )2-----------------

Ga

2πν( )4-----------------+ +=

Ge

Gs

Ga

G

σ

σ G2Δ-------=

G Ge, Gs, Ga

Δ

Page 90: Car Ride 2014

Adams/Car RideRoad-Profile Generation Tool

124

As explained in Reference 2, profiles for the left and right wheeltracks are obtained by the following method, which maintains the proper coherence between them:

1. Filtering and summing white-noise sources generates three uncorrelated profiles, as described statistically by the specified wheeltrack PSD, that is, the specified values of , , and . Adams/Car Ride scales them such that their PSD amplitudes are half of the wheeltrack PSD. The first of these is designated . It is not filtered further. The remaining two profiles are subsequently processed by filtering.

2. A cut-off wavenumber, , is established for the subsequent filtering as

: (3)

where is the correlation baselength. The recommended value for is 5.0 (m).

3. The second uncorrelated profile is filtered with a low-pass filter with cut-off wavenumber . The resulting profile is designated .

4. The third uncorrelated profile is filtered with a high-pass filter with cut-off wavenumber . The resulting profile is designated .

5. The left and right wheeltrack profiles, and , are then obtained from these three components:

(4)

(5)

Parameter Variables for Sayers Roughness Model

Example values for the parameters , , and . are shown in the following table, which is taken

from Appendix E of Reference 1. The terms flexible and rigid, as descriptions of surface types, approximately correspond to asphalt and Portland-cement concrete (PCC) roads, respectively. The symbol IRI in the table denotes International Roughness Index, which is a widely used road-roughness standard that was developed with The World Bank. The IRI is discussed in detail in Reference 3.

Table 5 Example Parameter Values for the Sayers Roughness Model

IRI Ge Gs Ga

Surface type

Smooth Flexible

75 1184 0 6 0

Flexible 150 2367 0 12 0.17

Ge Gs Ga

Zv1

ν2

ν21

LB 2-------------=

LB LBν2

Zv2ν2

ZcZL ZR

ZL Zv1 Zv2 Zc+ +=

ZR Zv1 Zv2 Zc–+=

Ge Gs Ga

inmi------ mm

km--------- m3

cycle------------- 10 6–× m

cycle------------- 10 6–× 1

m cycle×( )----------------------------- 10 6–×

Page 91: Car Ride 2014

125ToolsRoad-Profile Generation Tool

As explained in Reference 1, the range of values shown for the slope coefficient mainly reflects the roughness range covered by the roads in each category. The other two coefficients describe additional roughness increasing for very short and very long wavelengths. Amplitudes of very long wavelengths,

indicated by nonzero values of , might be associated with the quality of grading performed in

building the road. High amplitudes of very short wavelengths, typified by nonzero values of , are

commonly caused by surface defects that are extremely localized, such as faults, tar strips, and potholes.

Generating a Road Profile

To generate a road profile:

1. From the Ride menu, point to Tools, and then select Road-Profile Generation.

2. Press F1 and then follow the instructions in the dialog box help for Road-Profile Generation.

3. Select OK.

References 1. Gillespie, T.D., et.al., "Effects of Heavy-Vehicle Characteristics on Pavement Response and

Performance." NCHRP Report 353, Transportation Research Board, Washington D.C., 1993, 126 pp.

2. Sayers, M.W., "Dynamic Terrain Inputs to Predict Structural Integrity of Ground Vehicles." UMTRI Report No. UMTRI-88-16, April 1988, 114 pp.

3. Sayers, M.W. and Karamihas, S.M., "Interpretation of Road Roughness Profile Data." Final Report SPR-2 (159), Federal Highway Administration, Contract No. DTFH 61-92-C00143, January 1996.

4. MTS Systems Corporation: http://www.mts.com/ucm/groups/public/documents/library/mts_007569.pdf or Adams/Durability online help: Referencing Test Data

Rough Flexible

225 3551 0.003 20 0.20

Smooth Rigid

80 1263 0 1 0

Rigid 161 2541 0.1 20 0.25

Rough Rigid 241 3804 0.1 35 0.3

IRI Ge Gs Ga

Ga

Ge

Page 92: Car Ride 2014

Adams/Car RideRoad-Profile Generation Tool

126

Page 93: Car Ride 2014

Adams/Car Ride Functions

Page 94: Car Ride 2014

Adams/Car RideCOSA

2

COSA

The COSA({ARRAY}, REAL) function returns the real array. The each element of returned array equals cosign of each element of input array (first argument) multiplied by factor (second argument).

Format

COSA(array, factor)

Arguments

ExamplesCOSA({0,30,60},2)

This function builder function will create array on fly with array values (2.0, 1.732, 1.0).

CREAT_ARRAY

The CREATE_ARRAY(REAL, REAL, REAL) function returns the real array.

Format

CREATE_ARRAY(start, step, end)

Arguments

ExamplesCREATE_ARRAY(0.0, 5.0, 25.0)

This function builder function will create array on fly with array values (0.0, 5.0, 10.0, 15.0, 20.0, 25.0).

MULTA

The MULTA({ARRAY}, {ARRAY}) function returns the real array. The returned array is dot product of two input arrays.

array Input array.

factor Real number to multiply array.

start First element of array.

step Step to create subsequent array elements

end End value

Page 95: Car Ride 2014

3Adams/Car Ride FunctionsPOWA

Format

POWA(array1, array2)

Arguments

ExamplesMULTA({0.0,1.0,2.0},{0.0,1.0,2.0})

This function builder function will create array on fly with array values (0.0, 1.0, 4.0).

POWA

The POWA({ARRAY}, REAL) function returns the real array. The each element of returned array equals base (second argument) raised to each element of input array (first argument).

Format

POWA(array, base)

Arguments

ExamplesPOWA({0.0,1.0,2.0},2.0)

This function builder function will create array on fly with array values (1.0, 2.0, 4.0).

RIDE_INDEX

The vibration total value (PVTV: Point Vibration Total Value and OVTV: Overall Vibration Total Value) of weighted acceleration, determined from vibration co-ordinate can be calculated using RIDE_INDEX function that is implemented in Adams/Car Ride plug-in. This function is part of Adams expression builder and is listed under miscellaneous category. The use cases and calling syntax is listed below.

The first three real arrays list frequency weighted acceleration RMS values at three different locations (feet, seat and back rest) in three different directions X, Y and Z respectively. The data passed to these functions must be in MKS units. The first component of every first three array is weighted acceleration vector sum of signal. The next three components are simply frequency weighted RMS acceleration values in three orthogonal directions X, Y and Z. The array size of these first three real arrays should be four. You can directly use the return array of function RIDE_WARMS as input for these first three arrays.

array1 First input array.

array2 Second input array.

array Input array.

base Real number that will work as base value of power expression.

Page 96: Car Ride 2014

Adams/Car RideRIDE_INDEX

4

The fourth real array should be of size twelve and lists multiplying factors kx, ky and kz as suggested in ISO document for every location in the sequence feet, seat, back-rest and for OVTV respectively. The last string array should be of size greater than one. The RIDE_INDEX function is smart enough to return the real array of same size of this last array. The components of this last string array are listed here and you can pass them in any order you like:

MAX_WARMS: Returns maximum component value out of first three arrays

MIN_WARMS: Returns minimum component value out of first three arrays

PVTV_FEET: Returns vibration total value of weighted RMS acceleration at feet location

PVTV_SEAT: Returns vibration total value of weighted RMS acceleration at seat location

PVTV_BACK: Returns vibration total value of weighted RMS acceleration at seat back location

OVTV: Returns overall vibration total value

Format

RIDE_INDEX (ARRAY, ARRAY, ARRAY, ARRAY, ARRAY)

ExamplesRIDE_INDEX(RIDE_WARMS(

CREATE_ARRAY(0.0,0.125,1.0),UNITA(9),COSA(CREATE_ARRAY(0.0,45.0,360.0),1.0),SINA(CREATE_ARRAY(0.0,45.0,360.0),1.0),{"TIME","Wu","Wu","Wu"}),

RIDE_WARMS(CREATE_ARRAY(0.0,0.125,1.0),

Array Array of size four with frequency weighted acceleration RMS values in Resultant, X, Y and Z directions at feet.

You can pass return array of RIDE_WARMS.

Array Array of size four with frequency weighted acceleration RMS values in Resultant, X, Y and Z directions at seat.

You can pass return array of RIDE_WARMS.

Array Array of size four with frequency weighted acceleration RMS values in Resultant, X, Y and Z directions at back-rest. You can pass return array of RIDE_WARMS.

Array Array should be of size twelve and it lists multiplying factors kx, ky and kz as suggested in ISO document for every location in the sequence feet, seat, back-rest and for OVTV respectively.

Array Array of character should be of size greater than one. The RIDE_INDEX function is smart enough to return the real array of same size of this last array.

Page 97: Car Ride 2014

5Adams/Car Ride FunctionsRIDE_WARMS

UNITA(9),COSA(CREATE_ARRAY(0.0,45.0,360.0),1.0),SINA(CREATE_ARRAY(0.0,45.0,360.0),1.0),{"TIME","Wd","Wd","Wk"}),

RIDE_WARMS(CREATE_ARRAY(0.0,0.125,1.0),UNITA(9),COSA(CREATE_ARRAY(0.0,45.0,360.0),1.0),SINA(CREATE_ARRAY(0.0,45.0,360.0),1.0),{"TIME","Wc","Wu","Wu"}),

{1.0, 1.0, 1.0,1.4, 1.4, 1.0,1.0, 1.0, 1.0,1.0, 1.0, 1.0},{"PVTV_BACK","PVTV_SEAT","PVTV_FEET","MAX_WARMS","MIN_WARMS"})

This function builder function will return array {1.55, 1.77, 2.14, 2.14, 0.76}. It means, PVTV_BACK = 1.55, PVTV_SEAT = 1.77, PVTV_FEET = 2.14, MAX_WARMS = 2.14 and MIN_WARMS = 0.76.

RIDE_WARMS

The first real array is time or frequency sampling, second, third and fourth real arrays is acceleration signals at given location (feet, sheet or back rest) in three directions X, Y and Z respectively. The data passed to these functions must be in MKS units. The array size of these first four real arrays should be same.

The orientation of marker at given location should strictly follow the ISO guidelines for basic axes of the human body and the acceleration signals should be strictly passed to RIDE_WARMS in above specified order. The last character array is the key to select weighting curves and telling program about the domain of sampled data point (FREQ: Frequency, TIME: Time).

The RIDE_WARMS function returns the real array with four values. The returned array is {aVRMS, aXRMS, aYRMS, aZRMS}, where aVRMS is RMS value of resultant vector of XYZ responses, aXRMS is RMS value of X direction response, aYRMS is RMS value of Y direction response and aZRMS is RMS value of Z direction response respectively.

Format

RIDE_WARMS (ARRAY, ARRAY, ARRAY, ARRAY, ARRAY)

Array Array of time or Frequency sampling

Array Acceleration signal at feet location

Array Acceleration signal at seat location

Array Acceleration signal at back-rest location

Array Character array to select weighting curves and domain

Page 98: Car Ride 2014

Adams/Car RideRIDE_WEIGHTING

6

Examples

1. Time domain example

RIDE_WARMS(CREATE_ARRAY(0.0,0.125,1.0),ZEROA(9),ZEROA(9),SINA(CREATE_ARRAY(0.0,45.0,360.0),1.0),{"TIME","Wu","Wu","Wu"}

)

This function builder function will return array {0.89, 0.0, 0.0, 0.89}. It means, aVRMS= 0.89, aXRMS=0.0, aYRMS=0.0 and aZRMS=0.89.

2. Frequency domain example

RIDE_WARMS({1.0},ZEROA(1),ZEROA(1),UNITA(1),{"FREQ","Wu","Wu","Wu"}

)

This function builder function will return array {0.707, 0.0, 0.0, 0.707}. It means, aVRMS= 0.707, aXRMS=0.0, aYRMS=0.0 and aZRMS=0.707.

RIDE_WEIGHTING

This function is useful to verify various weighting curves used in RIDE_WARMS function.

Format

RIDE_WEIGHTING (ARRAY, string)

Examples

To return Wk weighting curve for 1/3 octave frequencies:

RIDE_WEIGHTING(POWA(CREATE_ARRAY(-17,1,26),1.2599), "Wk")

To return Wd weighting curve for 1/3 octave frequencies:

RIDE_WEIGHTING(POWA(CREATE_ARRAY(-17,1,26),1.2599), "Wd")

Array Array of frequency sampling points

string String indicating weighting curve to be returned out of:

"Wk", "Wd", "Wf", "Wc", "We", "Wj" and Unity curve "Wu".

Page 99: Car Ride 2014

7Adams/Car Ride FunctionsSCALEA

SCALEA

The SCALEA(ARRAY, REAL) function returns the real array. The returned array is scaled input array and the scaling is done by real input argument at second place.

Format

SCALEA(array, scale)

Arguments

ExamplesSCALEA({0.0,1.0,2.0},3.0)

This function builder function will create array on fly with array values (0.0, 3.0, 6.0).

SINA

The SINA({ARRAY}, REAL) function returns the real array. The each element of returned array equals sign of each element of input array (first argument) multiplied by factor (second argument).

Format

SINA(array, factor)

Arguments

array Input array. factor Real number to multiply array.

ExamplesSINA({0,30,60},2)

This function builder function will create array on fly with array values (0.0, 1.0, 1.732).

STATEMAT_WRITE

The STATEMAT_WRITE (Object, string, double, double, double, double) function write the state matrices A, B, C and D to file.

Format

STATEMAT_WRITE (Object, string, double, double, double, double)

array Input array.

scale Scaling factor

Page 100: Car Ride 2014

Adams/Car RideUNITA

8

Arguments

ExamplesSTATEMAT_WRITE(.onedof.VibrationAnalysis_1_analysis.STMAT_1,"stMAT",0.0,1.0,0.0,0.0)

This function builder function will write stMAT_a, stMAT_b, stMAT_c, and stMAT_d files in working directory.

UNITA

The UNITA(Integer) function returns the real array. The returned array is unity array (each element of returned array is one).

Format

UNITA(size)

Arguments

ExamplesUNITA(2)

This function builder function will create array on fly with array values (1.0, 1.0).

ZEROA

The ZEROA(Integer) function returns the real array. The returned array is zero array (each element of returned array is zero).

Format

ZEROA(size)

Object State matrix object

String File prefix

double Cut off frequency, if 0.0 then writes for all frequencies.

double Root flag

double Dummy (not used)

double Dummy (not used)

size Size of unity array.

Page 101: Car Ride 2014

9Adams/Car Ride FunctionsZEROA

Arguments

ExamplesZERO(2)

This function builder function will create array on fly with array values (0.0, 0.0).

size Size of zero array.

Page 102: Car Ride 2014

Adams/Car RideZEROA

10

Page 103: Car Ride 2014

123Dialog Box - F1 Help

Dialog Box - F1 Help

Page 104: Car Ride 2014

Adams/Car RideAbout the Bushing Model

124

About the Bushing Model Below is an outline of the frequency-dependent bushing model.

with

with

F1 C1 x⋅=

F2 C2 z⋅ d2 z·⋅+ d1 x· z·–( )⋅= =

Flin F1 F2+=

α C2C1------- β d2

d1------ γ d1

C1-------=;=;=

Flin C1 x⋅ d1 x· z·–( )⋅+ C1 xd1C1------- x· z·–( )⋅+

⋅ C1 x γ x· z·–( )⋅+( )⋅= = =

z·1

1 β+------------ x·

αγ--- z⋅–

⋅=

Page 105: Car Ride 2014

125Dialog Box - F1 HelpAbout the Bushing Model

Constant stiffness in frequency-dependent term of F_lin:

The static forces are computed by the splines from the property file; this is the first term, , of

. But the second term, , is computed with a constant value C1, obtained at the

zero position of the spline.

C1 x⋅Flin C1 γ x· z·–( )⋅⋅

Page 106: Car Ride 2014

Adams/Car RideAbout the Bushing Model

126

Reference frequency at 15 Hz for loss angle

The coefficients alpha, beta, gamma are linear scaled to obtain the loss angle at 15 Hz. The dynamic stiffness can not be controlled. The stiffening factor is coupled with the loss angle. For example:

Loss Angle [Deg]: Stiffening factor:

5 1.17

10 1.34

Page 107: Car Ride 2014

127Dialog Box - F1 HelpAbout the Bushing Model

Page 108: Car Ride 2014

Adams/Car RideAdams/Controls Plant Export

128

Adams/Controls Plant Export Exports the Adams/Controls plant files. Adams/Controls save the input and output information in an .m (for MATLAB) or .inf file (for Easy5).

For the option: Do the following:

Damper Specify the name of GSE Damper instance.

File Prefix Enter the prefix for the .m, and .inf files that Adams/Controls create.

Target Software Select one of the following:

• Easy5

• MATLAB

Adams Host Enter the name of the host machine from which the Adams plant is being exported. This host name is used if you choose TCP/IP-based communication to perform cosimulation or function evaluation between Adams and MATLAB or Easy5.

Page 109: Car Ride 2014

129Dialog Box - F1 HelpIsolator-Parameter Identification

Isolator-Parameter Identification

Ride → Tools → Isolator-Parameter Identification

Identifies the parameters of the bushing model for given measurements of dynamic stiffness and loss angle, depending on frequency. Learn more about Isolator-Parameter Identification Tool (IPIT).

For the option: Do the following:

File → Load File Load a bushing input file. See About Bushing Property File.

File → Save File Save the bushing to a file. See an Example Output Bushing Property File.

File → Export CMD Export the bushing CMD file. Use this option to create a user strategy by editing the file and to run the IPIT in batch mode and/or from command line. You can import the bushing CMD file in Adams/View as well.

File → Quit Quit IPIT tool.

Help → About About IPIT tool.

Help → About Adams/Car Ride IPIT

Help about Adams/Car Ride IPIT.

Input Parameters:

Calculate Frequency Response

Select to calculate the frequency response data with the current input parameters that are displayed in the text boxes. You can manually change those parameters and use this button to see the influence on the frequency response.

Error Control:

User Pars Enter the mscads optimizer user parameters to tune mscads for your problem

Convergence Tolerance Enter the tolerance for which the objective function is considered converged.

Max Function Evaluations Enter the allowed maximum function evaluations.

Max Cycles Enter the maximum cycles. The maximum cycles and frequency govern the simulation end time.

Integrator Error Enter the Adams/Solver integration error.

Objective Ratio Phase/CDyn

Specify the objective ratio between Loss Angle and dynamic stiffness.

Solver Control:

Optimizer Select Optimizer.

Solver Choice Select Solver.

Keep Files Select 'Yes' to save Adams/Solver related files.

Sensor Activate/Deactivate sensor.

Page 110: Car Ride 2014

Adams/Car RideIsolator-Parameter Identification

130

Method Select method to calculate the frequency responses.

Testrig Simulations Choose to run parallel or in sequence simulations for each amplitude.

Strategy Control:

Run 3 steps strategy If set to 'yes', the IPIT uses the built-in strategy to identify the parameters of the bushing model for the supplied measuring data.

Stop after step Set to 'No Stop' to run the three steps in sequence or select one of the other two options to stop between any identification step.

Go Select to start the identification process.

Stop Select to stop the identification process.

Plot Displays the frequency response of the model; the dynamic stiffness in the plot named Cdyn and the loss angle in the plot named Phase.

Data Displays the input file and the frequency response data.

For the option: Do the following:

Page 111: Car Ride 2014

131Dialog Box - F1 HelpComponent Analysis

Component AnalysisSets up a component analysis.

Results with 1 mm amplitude and 5 Hz

For the option: Do the following:

Component Assembly Select the component assembly you want to analyze. The menu shows all open component assemblies.

If it shows No component assemblies, then you must open or create an assembly. You can use either of the following ways to open or create an assembly:

• File -> New or File -> Open

• tool, described next

Right-click to display the following, left-click to select any of them:

• - Select an existing assembly and use it for the component analysis. This is an alternative method to selecting it directly from the Component Assembly menu.

• - Open an assembly from a file. Once loaded, Adams/Car Ride displays the assembly in the Component Assembly menu.

• - Create a new assembly. Once created, the new assembly will be displayed in the Component Assembly menu.

Output Prefix Enter a string that specifies the Analysis Output Name. The string can contain only alphanumeric characters and underscores (_).

Actuation Type This option is followed by either force or motion, indicating how the test rig is configured to stimulate the component during the analysis. This simply displays the setting in the Actuation Type pull-down menu on the Component Analysis: Set Up Test Rig dialog box.

Page 112: Car Ride 2014

Adams/Car RideComponent Analysis

132

Excitation Function Select an analysis type:

• Set of Frequencies - Perform a discrete frequency and amplitude sweep. You use this analysis to determine the loss energy and dynamic stiffness of a component.

• Range of Frequencies

• Continuous Sweep

• Quasi Static

• User Function

• Damper Sweep

If you select Set of Frequencies, Adams/Car Ride displays the following options:

Frequency Enter one or a list of frequency values. If you enter a list of frequencies, make sure that you separate each entry by a comma (1.0, 2.0, 3.0, ...).

Maximal Cycles Enter the maximum number of cycles to be performed during one analysis. If you enable the Energy Sensor, the simulation might stop before reaching the maximum number of cycles because the model has reached a steady-state condition.

Steps per Cycle Enter the desired number of steps per cycle.

Excitation Amplitude Enter one or a list of amplitude values. If you enter a list of amplitudes, make sure that you separate each entry by a comma (1.0, 2.0, 3.0, ...).

Phase Enter the phase of the excitation function. Adams/Car Ride applies the phase with an initial step.

Loop over Select the inner loop of a series of analyses (Amplitude or Frequency). This produces loss angle and dynamic stiffness over amplitude or frequency.

For the option: Do the following:

Page 113: Car Ride 2014

133Dialog Box - F1 HelpComponent Analysis

Energy Sensor Select one of the following:

• On

• Off

The analysis stops either as soon as loss energy converges or after completion of the maximum number of cycles.Use the Energy Sensor to watch the convergence of the force signal instead. Adams/Car Ride calculates the energy error, E, for one motion channel as follows:

E(cycle n) = (E(cycle n-1) + 7 * (loss_energy(n) - loss_energy(n-1)) / loss_energy(n)) / 8

If the energy error is less than 2.0e-3, the sensor stops the analysis because the model has converged on a steady-state response.

Measuring Method Select a method for measuring the loss angle and dynamic stiffness:

• Min-Max-Method - Combines the integral of the hysteresis with the minimum and maximum of the force. For a linear component, the result is usually equal to the fourier method. For a nonlinear component, the result diverges slightly. Learn more about the Min-Max Method.

• Fourier-Method - Is a first-order fourier analysis used to approximate the force signal with a harmonic force function. Learn more about the Fourier Method.

See the Force vs Displacement for Linear Damper.

If you select Range of Frequencies, Adams/Car Ride displays the following options:

Start Enter the start frequency.

Incr Enter the increment between frequencies.

End Enter the end frequency.

Maximal Cycles Enter the maximum number of cycles to be performed during one analysis. If you enable the Energy Sensor, the simulation might stop before reaching the maximum number of cycles because the model has reached a steady-state condition.

Steps per Cycle Enter the desired number of steps per cycle.

Excitation Amplitude Enter one or a list of amplitude values. Adams/Car Ride holds the amplitude constant during one analysis, and during the next analysis it chooses the next frequency in the list.

If you enter a list of amplitudes, make sure that you separate each entry by a comma (1.0, 2.0, 3.0, ...).

For the option: Do the following:

Page 114: Car Ride 2014

Adams/Car RideComponent Analysis

134

Phase Enter the phase of the excitation function. Adams/Car Ride applies the phase with an initial step.

Loop over Select the inner loop of a series of analyses (Amplitude or Frequency). This produces loss angle and dynamic stiffness over amplitude or frequency.

Energy Sensor The analysis stops either as soon as loss energy converges or after completion of the maximum number of cycles.

Measuring Method See the explanation for Measuring Method above.

If you select Continuous Sweep, Adams/Car Ride displays the following options:

Start Enter the start frequency.

End Enter the end frequency.

End Time Enter the end time for your simulation.

Number of Steps Enter the total number of steps. Make sure that you have sufficient output steps at the highest frequency so that important output data is not lost (anti-aliasing).

If you select Quasi Static, Adams/Car Ride displays the following options:(see example results for a quasi-static test)

End Time Enter the end time for your simulation.

Number of Steps Enter the total number of steps. Make sure that you have sufficient output steps at the highest frequency so that important output data is not lost (anti-aliasing).

Amplitude Enter the amplitude of the SAWTOOTH function.

Velocity Enter the velocity of the SAWTOOTH function.

Max. Acceleration Enter the maximum acceleration of the SAWTOOTH function at the reversal point.

For example:

y-axis: A = 1 mm, Vel = 0.5 mm/sec

z-axis: A = 2 mm, Vel = 0.5 mm/sec

Maximal acceleration: translational = 1 mm/sec

The max. acceleration should satisfy: (vel * vel) / acc < ampl / 4

The excitation function uses the HAVERSIN step to meet the reversal point.

If you select User Function, Adams/Car Ride displays the following options:

End Time Enter the end time for your simulation.

For the option: Do the following:

Page 115: Car Ride 2014

135Dialog Box - F1 HelpComponent Analysis

Number of Steps Enter the total number of steps. Make sure that you have sufficient output steps at the highest frequency so that important output data is not lost (anti-aliasing).

Amplitude Enter a function expression.

Select to use the Function or Expression Builder to define a function. For information on the Function or Expression Builder, see Function Builder.

If you select Damper Sweep, Adams/Car Ride displays the following options:(See example results for a Damper Sweep test.)

Frequency Alpha Factor Factor alpha determines the frequency acceleration. The displacement function is used for the Monroe Damper Model in the Chirps test:

x(time) = A * sin( 4 * PI * time /( 2 * T0 - time )), 0 < time < T/2

= -A * sin( 4 * PI * (T - time) / ( 2 * T0 - T + time)), T/2 < time < T

with:

• A = Amplitude

• T = End Time

• T0 = T / ( 4 * ( 1 - 1 / (2**alfa) ) )

End Time Enter the end time for your simulation.

Number of Steps Enter the total number of steps.

Other Monroe tests are:

Bleed: 1 Hz, A = 50 mm

Blow-off: 3 Hz, A = 50 mm

Compression: 12 Hz, A = 5 mm

Friction: damper velocity = 1 - 2 mm/sec.

VDA damper test at the test field:

Test: max. Damper velocity (mm/sec) - Amplitude (mm)

Friction 2.6 - 10

Gas Force 2.6 - 10

For the option: Do the following:

Page 116: Car Ride 2014

Adams/Car RideComponent Analysis

136

The gas and friction force definition:

Gas Force = (Fmax + Fmin) / 2

Friction Force = Fmax - Fmin

Forces Fmax and Fmin are measured at middle of max- and min displacement.

These tests can be performed with the Excitation function: Set of Frequencies with f = vmax/(2*PI*A) = 0.04138 Hz.

Excitation frequencies for the VDA Velocity Test with Amplitude = 50 mm:

Demand velocity (mm/sec): Excitation frequency (Hz):

52 0.1655211

131 0.4169860

262 0.8339719

393 1.2509579

524 1.6679438

1047 3.3327045

To get the pure damper forces, the results must be reduced by the gas force.

Keep Files Select to keep the analysis files on your disk.

Select to display a dialog box where you can add multi-line comments to any entity, to describe its purpose and function. Adams/Car Ride displays different comments dialog boxes, depending on the entity type for which you want to record comments:

• If recording comments for modeling entities in Standard Interface, Adams/Car Ride displays the Entity Comments dialog box.

• If recording comments for any other entity type, Adams/Car Ride displays the Modify Comment dialog box.

Learn more about Recording Comments.

For the option: Do the following:

Page 117: Car Ride 2014

137Dialog Box - F1 HelpComponent Analysis: Set Up Test Rig

Component Analysis: Set Up Test RigRide -> Component Analysis -> Component-Model Test Rig -> Set Up Test Rig

Lets you set up the test rig for a component analysis. Learn about the Component Test Rig.

Results with 1 mm amplitude and 5 Hz

For the option: Do the following:

Component Assembly Select the component assembly you want to analyze. The menu shows all open component assemblies.

If it shows No component assemblies, then you must open or create an assembly. You can use either of the following ways to open or create an assembly:

• File -> New or File -> Open

• tool, described next

Right-click to display the following, left-click to select any of them:

• - Select an existing assembly and use it for the component analysis. This is an alternative method to selecting it directly from the Component Assembly menu.

• - Load an assembly from a file. Adams/Car Ride displays the assembly in the Component Assembly menu.

• - Create a new assembly. Adams/Car Ride displays the assembly in the Component Assembly menu.

Actuation Type Select one of the following:

• Force Driven

• Motion Driven

If you select Force Driven, Adams/Car Ride displays the following options:

Constraint Select one of the following:

• Force - Implements a force in this direction.

• Locked - Locks this degree of freedom.

• Released - Releases this degree of freedom.

Page 118: Car Ride 2014

Adams/Car RideComponent Analysis: Set Up Test Rig

138

Initial Value Select whether you want to set the initial Displacement or Preload, and set its numerical value.

If you select Motion Driven, Adams/Car Ride displays the following options:

Constraint Select one of the following:

• Motion - Implements a motion in this direction.

• Locked - Locks this degree of freedom.

• Released - Releases this degree of freedom.

Initial Value Select whether you want to set the initial Displacement or Preload, and set its numerical value.

Select to display a dialog box where you can add multi-line comments to any entity, to describe its purpose and function. Adams/Car Ride displays different comments dialog boxes, depending on the entity type for which you want to record comments:

• If recording comments for modeling entities in Standard Interface, Adams/Car Ride displays the Entity Comments dialog box.

• If recording comments for any other entity type, Adams/Car Ride displays the Modify Comment dialog box.

Learn more about Recording Comments.

For the option: Do the following:

Page 119: Car Ride 2014

139Dialog Box - F1 HelpComponent Test Rig

Component Test RigThe component test rig has up to six prescribed motions to determine the dynamic stiffness and loss angle for each degree of freedom of an elastic component.

The test rig consists of an upper and lower part. The lower part is fixed to ground and the upper part is controlled by a six degree-of-freedom motion marker. You can activate or deactivate each motion degree of freedom.

The test component in the test-rig assembly defines its own mount location and communicates the location through a marker communicator. The upper mount point is at the upper part and the lower mount point is at the lower mount part of the test rig.

You can initialize multiple runs in one setup. For each simulation, you can compare measured data of dynamic stiffness and loss angle, or loss work, with the simulation result. This means that the component model being tested is excited with constant frequency and amplitude sinusoid until either of these conditions are met:

• The excitation has been repeated N times where N = the maximum number of cycles you set.

• The energy sensor is on and the loss angle has converged according to the error criteria in the help entry for the Energy Sensor.

Convergence means that the component model has reached steady-state behavior. Dynamic stiffness and loss angle are only defined for a steady-state condition.

The test rig is also used for quasi-static analyses, which maintain a constant velocity motion between a minimum and maximum displacement. You can define a preload for each motion degree of freedom or for an initial displacement. The motion can be a constant-frequency or a linear-frequency sweep. The motion is defined between the marker lower_mount_point and upper_mount_point with respect to cfs_testrig_reference.

Analysis Types and Test-Rig Setup

Note: You must set up the test rig before you can run a meaningful analysis.

Test rig setup: Excitation function: Driver type: Results:

Analysis types:

Constr. Initial Displ.

Preload Amplitude Phase Motion Force Loss Angle

Std. Req

Set of Frequencies

x x x A set of amplitudes

Initial Step

x x x x

Range of Frequencies

x x x A set of amplitudes

Initial Step

x - x x

Page 120: Car Ride 2014

Adams/Car RideComponent Test Rig

140

The test-rig setup determines the constraints for each component as motion, locked, or constraint released. The initial displacement and preload are exclusive options. The initial displacement or preload is applied during the initial static and its values are used as the start condition for the subsequent analysis.

The constraints you can choose depend on the actuation type:

• Motion - The available constraints are: Locked, Released, or Motion. The initial displacement or preload is only for Locked or Motion constraints.

• Force - The available constraints are: Locked, Released, or Force. The initial displacement or preload is only for Locked constraint. The Force option allows you to enter a force offset value.

Excitation Function

The excitation function is defined in the dialog box, Component Analysis.

Amplitude - The amplitude is a single value or a set of amplitudes separated by commas. Each amplitude performs an analysis with the same test rig setup.

Phase - The phase of a sinusoidal motion during a constant or sweep frequency is achieved in different ways. The motion always starts with velocity = 0 and increases in a quarter of a period to the specified amplitude value. The sine function starts after a fourth of a period minus the phase shift value. The initial displacement or preload is held during the static analysis. The sinusoidal motion starts at the initial displacement.

Continuous Sweep

x x x A set of amplitudes

Direct x - - x

Quasi Static x x x A set of amplitudes

Initial Step

x - - x

User Function

x x x - - x x - x

Damper Sweep

x x x A set of amplitudes

- x - - x

Test rig setup: Excitation function: Driver type: Results:

Page 121: Car Ride 2014

141Dialog Box - F1 HelpComponent Test Rig

For example see the following figure: phase 0, 45 and 90 Deg, 1 Hz, initial displ. 0.

Direct - This method is used for the continuous sweep only. The sinusoidal motion starts with its phase and its initial displacement at time = 0, which causes a shift in displacement. The shift can be compensated with the initial displacement.

d = - amplitude * sin(phase)

If a preload was defined, the compensation is iterative.

Page 122: Car Ride 2014

Adams/Car RideComponent Test Rig

142

For example see the following figure: phase 0, 45 and 90 Deg, 1 Hz, initial displ. 0.

Results

Each analysis contains request data of the test rig. The test rig has two measure points: at the upper mount point, the I marker, and at the lower mount point, the J marker.

Name: Component: Units: Comments:

I_Force fx, fy, fz FORCE Force on I marker of motion generator Test_MOTION_* with respect to cfs_testrig_reference

= tx, ty, tz TORQUE Torque on I marker of motion generator Test_MOTION_t* with respect to cfs_testrig_reference

I_Displacement x, y, z LENGTH Displacement between I and J marker of Test_MOTION_* with respect to cfs_testrig_reference

= ax, ay, az ANGLE Angle with respect to cfs_testrig_reference

I_Velocity vx, vy, vz VELOCITY Velocity on I marker with respect to cfs_testrig_reference

Page 123: Car Ride 2014

143Dialog Box - F1 HelpComponent Test Rig

Construction Frames

The cfs_testrig_reference is the basis for motion and measurements.

= wx, wy, wz ANGULAR VELOCITY

Angular velocity

I_Acceleration acc_x, acc_y, acc_z ACCELERATION Acceleration on I marker with respect to cfs_testrig_reference

= dwx, dwy, dwz ANGULAR ACCELERATION

Angular acceleration

J_Force fx, fy, fz FORCE Force on J marker with respect to cfs_testrig_reference

= tx, ty, tz TORQUE

Force_Characteristics_$disp_comp

dyn_stiffness loss_angle

fmin

fmax

loss_energy

strain_energy

STIFFNESS

ANGLE

FORCE/TORQUE

FORCE/TORQUE

-

-

MinMax Method: user 112

Fourier Method: user 113

TestMotion_$disp_comp x, y, z,

ax, ay, az

AMPLITUDE

FREQUENCY

-

Analysis name = Transfer_Function_i

Result name = Force_Characteristics_$disp_comp

dyn_stiffness

loss_angle

Frequency

STIFFNESS

ANGLE

FREQUENCY

Last values of a Set or Range of Frequency Sweep i

Name:Location

dependency: Expression: Reference(s):

cfs_testrig_reference Delta location from coordinate

0,0,0 cis_upper_mount_point

Name: Component: Units: Comments:

Page 124: Car Ride 2014

Adams/Car RideComponent Test Rig

144

Expressions

The location expressions for cfs_lower_mount_point and cfs_upper_mount_point are nonstandard Adams/Car expressions. The cis_lower_mount_point and cis_upper_mount_point are marker communicators.

The displacement between cfs_upper_mount_point and cfs_testrig_reference is a zero displacement.

Test Rig Communicators

cfs_lower_mount_point Delta location from coordinate

0,0,0 cis_lower_mount_point

cfs_upper_mount_point Delta location from coordinate

0,0,0 cis_upper_mount_point

Name: Class:From minor

role: Matching name: Comment:

cis_lower_mount_point

marker inherit lower_mount_point mount point of component

cis_upper_mount_point

marker inherit upper_mount_point mount point of component

cos_lower mount inherit lower mount part

cos_upper mount inherit upper mount part

cis_active_x, _y, _z, _ax, _ay, _az

parameter

integer

inherit active_x, _y, _z, _ax, _ay, _az

constraint

active = 1,

deactive = 0

Name:Location

dependency: Expression: Reference(s):

Page 125: Car Ride 2014

145Dialog Box - F1 HelpExample Bushing Property File

Example Bushing Property FileThe following is a sample input Bushing property file (extension .gbu). This sample file contains the minimum set of required data.

$-----------------------------------------------------MDI_HEADER [MDI_HEADER] FILE_TYPE = 'gbu' FILE_VERSION = 2.0 FILE_FORMAT = 'ASCII' $-----------------------------------------------------UNITS [UNITS] LENGTH = 'mm' FORCE = 'newton' ANGLE = 'degrees' MASS = 'kg' TIME = 'second' $-----------------------------------------------------GENERAL [GENERAL] DEFINITION = '.aride.attachment.ac_general_bushing' BUSHING_SHAPE = 0BUSHING_COUPLING = 2$------------------------------------------------------------DAMPING[DAMPING] X_LOSS_ANGLE = 0.0 Y_LOSS_ANGLE = 0.0 Z_LOSS_ANGLE = 0.0 TX_LOSS_ANGLE = 0.0 TY_LOSS_ANGLE = 0.0 TZ_LOSS_ANGLE = 0.0$------------------------------------------------------------PRELOAD[PRELOAD] X_PRELOAD = 0.0 Y_PRELOAD = 0.0 Z_PRELOAD = 0.0 TX_PRELOAD = 0.0 TY_PRELOAD = 0.0 TZ_PRELOAD = 0.0$-------------------------------------------------------------OFFSET[OFFSET] X_OFFSET = 0.0 Y_OFFSET = 0.0 Z_OFFSET = 0.0 TX_OFFSET = 0.0 TY_OFFSET = 0.0 TZ_OFFSET = 0.0$-------------------------------------------------------------SPLINE[SPLINE_SCALES]FX_CURVE_SCALE = 1.0FY_CURVE_SCALE = 1.0FZ_CURVE_SCALE = 1.0TX_CURVE_SCALE = 1.0TY_CURVE_SCALE = 1.0TZ_CURVE_SCALE = 1.0

Page 126: Car Ride 2014

Adams/Car RideExample Bushing Property File

146

$----------------------------------------------------------BOUC-WEN[HYST_SCALES]X_HYST_SCALE = 1.0Y_HYST_SCALE = 1.0Z_HYST_SCALE = 1.0TX_HYST_SCALE = 1.0TY_HYST_SCALE = 1.0TZ_HYST_SCALE = 1.0$-------------------------------------------------------------TFSISO[TFSISO_SCALES]X_TFSISO_SCALE = 1.0Y_TFSISO_SCALE = 1.0Z_TFSISO_SCALE = 1.0TX_TFSISO_SCALE = 1.0TY_TFSISO_SCALE = 1.0TZ_TFSISO_SCALE = 1.0$-----------------------------------------------------------FX_CURVE[FX_CURVE]{ x fx}-10.0 -2700.0-8.0 -2160.0-6.0 -1620.0-4.0 -1080.0-2.0 -540.00.0 0.02.0 540.04.0 1080.06.0 1620.08.0 2160.010.0 2700.0$-----------------------------------------------------------FY_CURVE[FY_CURVE]{ y fy}-10.0 -2700.0-8.0 -2160.0-6.0 -1620.0-4.0 -1080.0-2.0 -540.00.0 0.02.0 540.04.0 1080.06.0 1620.08.0 2160.010.0 2700.0$-----------------------------------------------------------FZ_CURVE[FZ_CURVE]{ z fz}-10.0 -2700.0-8.0 -2160.0-6.0 -1620.0-4.0 -1080.0-2.0 -540.00.0 0.02.0 540.0

Page 127: Car Ride 2014

147Dialog Box - F1 HelpExample Bushing Property File

4.0 1080.06.0 1620.08.0 2160.010.0 2700.0$-----------------------------------------------------------TX_CURVE[TX_CURVE]{ ax tx}-45.0 -36000.0-36.0 -28800.0-27.0 -21600.0-18.0 -14400.0-9.0 -7200.00.0 0.09.0 7200.018.0 14400.027.0 21600.036.0 28800.045.0 36000.0$-----------------------------------------------------------TY_CURVE[TY_CURVE]{ ay ty}-45.0 -36000.0-36.0 -28800.0-27.0 -21600.0-18.0 -14400.0-9.0 -7200.00.0 0.09.0 7200.018.0 14400.027.0 21600.036.0 28800.045.0 36000.0$-----------------------------------------------------------TZ_CURVE[TZ_CURVE]{ az tz}-45.0 -36000.0-36.0 -28800.0-27.0 -21600.0-18.0 -14400.0-9.0 -7200.00.0 0.09.0 7200.018.0 14400.027.0 21600.036.0 28800.045.0 36000.0$------------------------------------------------BUSHING_PARAMETERS [BUSHING_PARAMETERS] X_ALPHA = 0.5 X_BETA =20 X_GAMMA =-20 X_ZETA = 1.0 X_OMEGA =10.0 X_A =1.0

Page 128: Car Ride 2014

Adams/Car RideExample Bushing Property File

148

X_N =2.0 X_NUM =3.0,2.0,3.0 X_DEN =4.0,1.0,5.0,6.0 Y_ALPHA = 0.5 Y_BETA =20 Y_GAMMA =-20 Y_ZETA = 1.0 Y_OMEGA =10.0 Y_A =1.0 Y_N =2.0 Y_NUM =3.0,2.0,3.0 Y_DEN =4.0,1.0,5.0,6.0 Z_ALPHA = 0.5 Z_BETA =20 Z_GAMMA =-20 Z_ZETA = 1.0 Z_OMEGA =10.0 Z_A =1.0 Z_N =2.0 Z_NUM =3.0,2.0,3.0 Z_DEN =4.0,1.0,5.0,6.0 AX_ALPHA = 0.5 AX_BETA =20 AX_GAMMA =-20 AX_ZETA = 1.0 AX_OMEGA =10.0 AX_A =1.0 AX_N =2.0 AX_NUM =3.0,2.0,3.0 AX_DEN =4.0,1.0,5.0,6.0 AY_ALPHA = 0.5 AY_BETA =20 AY_GAMMA =-20 AY_ZETA = 1.0 AY_OMEGA =10.0 AY_A =1.0 AY_N =2.0 AY_NUM =3.0,2.0,3.0 AY_DEN =4.0,1.0,5.0,6.0 AZ_ALPHA = 0.5 AZ_BETA =20 AZ_GAMMA =-20 AZ_ZETA = 1.0 AZ_OMEGA =10.0 AZ_A =1.0 AZ_N =2.0 AZ_NUM =3.0,2.0,3.0 AZ_DEN =4.0,1.0,5.0,6.0

Page 129: Car Ride 2014

149Dialog Box - F1 HelpExample Input Bushing Property File for Identification

Example Input Bushing Property File for IdentificationThe following is a sample input Bushing property file (extension .gbu). This sample file contains the minimum set of required data.

$-----------------------------------------------------MDI_HEADER [MDI_HEADER] FILE_TYPE = 'gbu' FILE_VERSION = 2.0 FILE_FORMAT = 'ASCII' $-----------------------------------------------------UNITS [UNITS] LENGTH = 'mm' FORCE = 'newton' ANGLE = 'degrees' MASS = 'kg' TIME = 'second' $-----------------------------------------------------GENERAL [GENERAL] DEFINITION = '.aride.attachment.ac_general_bushing' BUSHING_COORDINATE = 'z' BUSHING_COUPLING = 2$------------------------------------------------------------DAMPING[DAMPING] X_LOSS_ANGLE = 0.0 Y_LOSS_ANGLE = 0.0 Z_LOSS_ANGLE = 0.0 TX_LOSS_ANGLE = 0.0 TY_LOSS_ANGLE = 0.0 TZ_LOSS_ANGLE = 0.0$------------------------------------------------------------PRELOAD[PRELOAD] X_PRELOAD = 0.0 Y_PRELOAD = 0.0 Z_PRELOAD = 0.0 TX_PRELOAD = 0.0 TY_PRELOAD = 0.0 TZ_PRELOAD = 0.0$-------------------------------------------------------------OFFSET[OFFSET] X_OFFSET = 0.0 Y_OFFSET = 0.0 Z_OFFSET = 0.0 TX_OFFSET = 0.0 TY_OFFSET = 0.0 TZ_OFFSET = 0.0$-------------------------------------------------------------SPLINE[SPLINE_SCALES]FX_CURVE_SCALE = 1.0FY_CURVE_SCALE = 1.0FZ_CURVE_SCALE = 1.0TX_CURVE_SCALE = 1.0TY_CURVE_SCALE = 1.0TZ_CURVE_SCALE = 1.0

Page 130: Car Ride 2014

Adams/Car RideExample Input Bushing Property File for Identification

150

$----------------------------------------------------------BOUC-WEN[HYST_SCALES]X_HYST_SCALE = 1.0Y_HYST_SCALE = 1.0Z_HYST_SCALE = 1.0TX_HYST_SCALE = 1.0TY_HYST_SCALE = 1.0TZ_HYST_SCALE = 1.0$-------------------------------------------------------------TFSISO[TFSISO_SCALES]X_TFSISO_SCALE = 1.0Y_TFSISO_SCALE = 1.0Z_TFSISO_SCALE = 1.0TX_TFSISO_SCALE = 1.0TY_TFSISO_SCALE = 1.0TZ_TFSISO_SCALE = 1.0$-----------------------------------------------------------FX_CURVE[FX_CURVE]{ x fx}-10.0 -2700.0-8.0 -2160.0-6.0 -1620.0-4.0 -1080.0-2.0 -540.00.0 0.02.0 540.04.0 1080.06.0 1620.08.0 2160.010.0 2700.0$-----------------------------------------------------------FY_CURVE[FY_CURVE]{ y fy}-10.0 -2700.0-8.0 -2160.0-6.0 -1620.0-4.0 -1080.0-2.0 -540.00.0 0.02.0 540.04.0 1080.06.0 1620.08.0 2160.010.0 2700.0$-----------------------------------------------------------FZ_CURVE[FZ_CURVE]{ z fz}-10.0 -2700.0-8.0 -2160.0-6.0 -1620.0-4.0 -1080.0-2.0 -540.00.0 0.02.0 540.0

Page 131: Car Ride 2014

151Dialog Box - F1 HelpExample Input Bushing Property File for Identification

4.0 1080.06.0 1620.08.0 2160.010.0 2700.0$-----------------------------------------------------------TX_CURVE[TX_CURVE]{ ax tx}-45.0 -36000.0-36.0 -28800.0-27.0 -21600.0-18.0 -14400.0-9.0 -7200.00.0 0.09.0 7200.018.0 14400.027.0 21600.036.0 28800.045.0 36000.0$-----------------------------------------------------------TY_CURVE[TY_CURVE]{ ay ty}-45.0 -36000.0-36.0 -28800.0-27.0 -21600.0-18.0 -14400.0-9.0 -7200.00.0 0.09.0 7200.018.0 14400.027.0 21600.036.0 28800.045.0 36000.0$-----------------------------------------------------------TZ_CURVE[TZ_CURVE]{ az tz}-45.0 -36000.0-36.0 -28800.0-27.0 -21600.0-18.0 -14400.0-9.0 -7200.00.0 0.09.0 7200.018.0 14400.027.0 21600.036.0 28800.045.0 36000.0$------------------------------------------------BUSHING_PARAMETERS [BUSHING_PARAMETERS] X_ALPHA = 0.5 X_BETA = 20 X_GAMMA =-20 X_ZETA = 1.0 X_OMEGA =10.0 X_A =1.0

Page 132: Car Ride 2014

Adams/Car RideExample Input Bushing Property File for Identification

152

X_N =2.0 X_NUM =3.0,2.0,3.0 X_DEN =4.0,1.0,5.0,6.0 Y_ALPHA = 0.5 Y_BETA =20 Y_GAMMA =-20 Y_ZETA = 1.0 Y_OMEGA =10.0 Y_A =1.0 Y_N =2.0 Y_NUM =3.0,2.0,3.0 Y_DEN =4.0,1.0,5.0,6.0 Z_ALPHA = 0.5 Z_BETA =20 Z_GAMMA =-20 Z_ZETA = 1.0 Z_OMEGA =10.0 Z_A =1.0 Z_N =2.0 Z_NUM =3.0,2.0,3.0 Z_DEN =4.0,1.0,5.0,6.0 AX_ALPHA = 0.5 AX_BETA =20 AX_GAMMA =-20 AX_ZETA = 1.0 AX_OMEGA =10.0 AX_A =1.0 AX_N =2.0 AX_NUM =3.0,2.0,3.0 AX_DEN =4.0,1.0,5.0,6.0 AY_ALPHA = 0.5 AY_BETA =20 AY_GAMMA =-20 AY_ZETA = 1.0 AY_OMEGA =10.0 AY_A =1.0 AY_N =2.0 AY_NUM =3.0,2.0,3.0 AY_DEN =4.0,1.0,5.0,6.0 AZ_ALPHA = 0.5 AZ_BETA =20 AZ_GAMMA =-20 AZ_ZETA = 1.0 AZ_OMEGA =10.0 AZ_A =1.0 AZ_N =2.0 AZ_NUM =3.0,2.0,3.0 AZ_DEN =4.0,1.0,5.0,6.0 --------------------------------------------------BUSHING_TEST_DATA

Page 133: Car Ride 2014

153Dialog Box - F1 HelpExample Input Bushing Property File for Identification

[BUSHING_TEST_DATA]

{amplitude frequency cdyn phase}

0.100000 1.000000 392.000000 1.900000

0.100000 2.000000 393.000000 3.800000

0.100000 3.000000 393.000000 4.800000

... continue

0.100000 40.000000 773.000000 4.700000

0.500000 1.000000 389.000000 2.800000

0.500000 2.000000 386.000000 4.100000

0.500000 3.000000 385.000000 5.800000

... continue

0.500000 40.000000 734.000000 4.800000

1.000000 1.000000 379.000000 3.100000

1.000000 2.000000 377.000000 4.800000

1.000000 3.000000 378.000000 6.900000

... continue

1.000000 40.000000 700.000000 4.700000

Page 134: Car Ride 2014

Adams/Car RideExample Input Bushing Property File for Identification - one direction

154

Example Input Bushing Property File for Identification - one directionThe following is a sample input Bushing property file (extension .gbu). This sample file contains the minimum set of required data.

$-----------------------------------------------------MDI_HEADER [MDI_HEADER] FILE_TYPE = 'gbu' FILE_VERSION = 2.0 FILE_FORMAT = 'ASCII' $-----------------------------------------------------UNITS [UNITS] LENGTH = 'mm' FORCE = 'newton' ANGLE = 'degrees' MASS = 'kg' TIME = 'second' $-----------------------------------------------------GENERAL [GENERAL] DEFINITION = '.aride.attachment.ac_general_bushing' BUSHING_COORDINATE = 'z' BUSHING_COUPLING = 2$-------------------------------------------------------------SPLINE[SPLINE_SCALES]FX_CURVE_SCALE = 1.0FY_CURVE_SCALE = 1.0FZ_CURVE_SCALE = 1.0TX_CURVE_SCALE = 1.0TY_CURVE_SCALE = 1.0TZ_CURVE_SCALE = 1.0$----------------------------------------------------------BOUC-WEN[HYST_SCALES]X_HYST_SCALE = 1.0Y_HYST_SCALE = 1.0Z_HYST_SCALE = 1.0TX_HYST_SCALE = 1.0TY_HYST_SCALE = 1.0TZ_HYST_SCALE = 1.0$-------------------------------------------------------------TFSISO[TFSISO_SCALES]X_TFSISO_SCALE = 1.0Y_TFSISO_SCALE = 1.0Z_TFSISO_SCALE = 1.0TX_TFSISO_SCALE = 1.0TY_TFSISO_SCALE = 1.0TZ_TFSISO_SCALE = 1.0$-----------------------------------------------------------FZ_CURVE[FZ_CURVE]{ z fz}-10.0 -2700.0 -8.0 -2160.0 -6.0 -1620.0 -4.0 -1080.0

Page 135: Car Ride 2014

155Dialog Box - F1 HelpExample Input Bushing Property File for Identification - one direction

-2.0 -540.0 0.0 0.0 2.0 540.0 4.0 1080.0 6.0 1620.0 8.0 2160.0 10.0 2700.0$------------------------------------------------BUSHING_PARAMETERS [BUSHING_PARAMETERS] Z_ALPHA = 1000.0 Z_BETA = 1.7 Z_GAMMA =-0.2 Z_ZETA = 0.0 Z_OMEGA = 0.0 Z_A = 1.0 Z_N = 0.2 Z_NUM = 0.0,0.0 Z_DEN = 0.0,1.0$--------------------------------------------------BUSHING_TEST_DATA[BUSHING_TEST_DATA]

{amplitude frequency cdyn phase}

0.100000 1.000000 392.000000 1.900000

0.100000 2.000000 393.000000 3.800000

0.100000 3.000000 393.000000 4.800000

... continue

0.100000 40.000000 773.000000 4.700000

0.500000 1.000000 389.000000 2.800000

0.500000 2.000000 386.000000 4.100000

0.500000 3.000000 385.000000 5.800000

... continue

0.500000 40.000000 734.000000 4.800000

1.000000 1.000000 379.000000 3.100000

1.000000 2.000000 377.000000 4.800000

1.000000 3.000000 378.000000 6.900000

... continue

1.000000 40.000000 700.000000 4.700000

Page 136: Car Ride 2014

Adams/Car RideExample Output Bushing Property File

156

Example Output Bushing Property File The following is an example output bushing property file.

$-----------------------------------------------------MDI_HEADER [MDI_HEADER] FILE_TYPE = 'gbu' FILE_VERSION = 2.0 FILE_FORMAT = 'ASCII' $-----------------------------------------------------UNITS [UNITS] LENGTH = 'mm' FORCE = 'newton' ANGLE = 'degrees' MASS = 'kg' TIME = 'second' $-----------------------------------------------------GENERAL [GENERAL] DEFINITION = '.aride.attachment.ac_general_bushing' BUSHING_COORDINATE = 'z' BUSHING_SHAPE = 0BUSHING_COUPLING = 1$------------------------------------------------------------DAMPING[DAMPING] X_LOSS_ANGLE = 0.0 Y_LOSS_ANGLE = 0.0 Z_LOSS_ANGLE = 0.0 TX_LOSS_ANGLE = 0.0 TY_LOSS_ANGLE = 0.0 TZ_LOSS_ANGLE = 0.0$------------------------------------------------------------PRELOAD[PRELOAD] X_PRELOAD = 0.0 Y_PRELOAD = 0.0 Z_PRELOAD = 0.0 TX_PRELOAD = 0.0 TY_PRELOAD = 0.0 TZ_PRELOAD = 0.0$-------------------------------------------------------------OFFSET[OFFSET] X_OFFSET = 0.0 Y_OFFSET = 0.0 Z_OFFSET = 0.0 TX_OFFSET = 0.0 TY_OFFSET = 0.0 TZ_OFFSET = 0.0$-------------------------------------------------------------SPLINE[SPLINE_SCALES]FX_CURVE_SCALE = 1.0FY_CURVE_SCALE = 1.0FZ_CURVE_SCALE = 1.0TX_CURVE_SCALE = 1.0TY_CURVE_SCALE = 1.0TZ_CURVE_SCALE = 1.0$----------------------------------------------------------BOUC-WEN

Page 137: Car Ride 2014

157Dialog Box - F1 HelpExample Output Bushing Property File

[HYST_SCALES]X_HYST_SCALE = 1.0Y_HYST_SCALE = 1.0Z_HYST_SCALE = 1.0TX_HYST_SCALE = 1.0TY_HYST_SCALE = 1.0TZ_HYST_SCALE = 1.0$-------------------------------------------------------------TFSISO[TFSISO_SCALES]X_TFSISO_SCALE = 1.0Y_TFSISO_SCALE = 1.0Z_TFSISO_SCALE = 1.0TX_TFSISO_SCALE = 1.0TY_TFSISO_SCALE = 1.0TZ_TFSISO_SCALE = 1.0

$-----------------------------------------------------------FX_CURVE[FX_CURVE]{ x fx}-10.0 -2700.0-8.0 -2160.0-6.0 -1620.0-4.0 -1080.0-2.0 -540.00.0 0.02.0 540.04.0 1080.06.0 1620.08.0 2160.010.0 2700.0$-----------------------------------------------------------FY_CURVE[FY_CURVE]{ y fy}-10.0 -2700.0-8.0 -2160.0-6.0 -1620.0-4.0 -1080.0-2.0 -540.00.0 0.02.0 540.04.0 1080.06.0 1620.08.0 2160.010.0 2700.0$-----------------------------------------------------------FZ_CURVE[FZ_CURVE]{ z fz}-10.0 -2700.0-8.0 -2160.0-6.0 -1620.0-4.0 -1080.0-2.0 -540.00.0 0.02.0 540.0

Page 138: Car Ride 2014

Adams/Car RideExample Output Bushing Property File

158

4.0 1080.06.0 1620.08.0 2160.010.0 2700.0$-----------------------------------------------------------TX_CURVE[TX_CURVE]{ ax tx}-45.0 -36000.0-36.0 -28800.0-27.0 -21600.0-18.0 -14400.0-9.0 -7200.00.0 0.09.0 7200.018.0 14400.027.0 21600.036.0 28800.045.0 36000.0$-----------------------------------------------------------TY_CURVE[TY_CURVE]{ ay ty}-45.0 -36000.0-36.0 -28800.0-27.0 -21600.0-18.0 -14400.0-9.0 -7200.00.0 0.09.0 7200.018.0 14400.027.0 21600.036.0 28800.045.0 36000.0$-----------------------------------------------------------TZ_CURVE[TZ_CURVE]{ az tz}-45.0 -36000.0-36.0 -28800.0-27.0 -21600.0-18.0 -14400.0-9.0 -7200.00.0 0.09.0 7200.018.0 14400.027.0 21600.036.0 28800.045.0 36000.0$------------------------------------------------BUSHING_PARAMETERS [BUSHING_PARAMETERS] X_ALPHA = 0.5 X_BETA =20 X_GAMMA =-20 X_ZETA = 1.0 X_OMEGA =10.0 X_A =1.0

Page 139: Car Ride 2014

159Dialog Box - F1 HelpExample Output Bushing Property File

X_N =2.0 X_NUM =3.0,2.0,3.0 X_DEN =4.0,1.0,5.0,6.0 Y_ALPHA = 0.5 Y_BETA =20 Y_GAMMA =-20 Y_ZETA = 1.0 Y_OMEGA =10.0 Y_A =1.0 Y_N =2.0 Y_NUM =3.0,2.0,3.0 Y_DEN =4.0,1.0,5.0,6.0 Z_ALPHA = 0.5 Z_BETA =20 Z_GAMMA =-20 Z_ZETA = 1.0 Z_OMEGA =10.0 Z_A =1.0 Z_N =2.0 Z_NUM =3.0,2.0,3.0 Z_DEN =4.0,1.0,5.0,6.0 AX_ALPHA = 0.5 AX_BETA =20 AX_GAMMA =-20 AX_ZETA = 1.0 AX_OMEGA =10.0 AX_A =1.0 AX_N =2.0 AX_NUM =3.0,2.0,3.0 AX_DEN =4.0,1.0,5.0,6.0 AY_ALPHA = 0.5 AY_BETA =20 AY_GAMMA =-20 AY_ZETA = 1.0 AY_OMEGA =10.0 AY_A =1.0 AY_N =2.0 AY_NUM =3.0,2.0,3.0 AY_DEN =4.0,1.0,5.0,6.0 AZ_ALPHA = 0.5 AZ_BETA =20 AZ_GAMMA =-20 AZ_ZETA = 1.0 AZ_OMEGA =10.0 AZ_A =1.0 AZ_N =2.0 AZ_NUM =3.0,2.0,3.0 AZ_DEN =4.0,1.0,5.0,6.0$-------------------------------------BUSHING_IDENTIFICATION_DATA

Page 140: Car Ride 2014

Adams/Car RideExample Output Bushing Property File

160

[BUSHING_IDENTIFICATION_DATA]

$--------------------------------------------------BUSHING_TEST_DATA[BUSHING_TEST_DATA]

{amplitude frequency cdyn phase}

0.100000 1.000000 404.863819 1.243071

0.100000 2.000000 399.691551 2.618614

0.100000 3.000000 388.455029 4.605679

... continue

0.100000 40.000000 713.285910 6.099968

0.500000 1.000000 404.772004 1.302907

0.500000 2.000000 399.309176 2.830528

0.500000 3.000000 389.903747 4.774778

... continue

0.500000 40.000000 716.810500 6.126563

1.000000 1.000000 404.777324 1.347649

1.000000 2.000000 399.296585 3.024592

1.000000 3.000000 390.207932 5.272207

... continue

1.000000 40.000000 700.288389 6.281555

{amplitude frequency cdyn phase}

0.100000 1.000000 392.000000 1.900000

0.100000 2.000000 393.000000 3.800000

0.100000 3.000000 393.000000 4.800000

... continue

0.100000 40.000000 773.000000 4.700000

0.500000 1.000000 389.000000 2.800000

0.500000 2.000000 386.000000 4.100000

0.500000 3.000000 385.000000 5.800000

... continue

0.500000 40.000000 734.000000 4.800000

1.000000 1.000000 379.000000 3.100000

1.000000 2.000000 377.000000 4.800000

Page 141: Car Ride 2014

161Dialog Box - F1 HelpExample Output Bushing Property File

$-------------------------------------------------BUSHING_SCALE_DATA[BUSHING_SCALE_DATA]

1.000000 3.000000 378.000000 6.900000

... continue

1.000000 40.000000 700.000000 4.700000

{amplitude frequency cdyn phase}

0.100000 1.000000 1.000000 1.000000

0.100000 2.000000 1.000000 1.000000

0.100000 3.000000 1.000000 1.000000

... continue

0.100000 40.000000 1.000000 1.000000

0.500000 1.000000 1.000000 1.000000

0.500000 2.000000 1.000000 1.000000

0.500000 3.000000 1.000000 1.000000

... continue

0.500000 40.000000 1.000000 1.000000

1.000000 1.000000 1.000000 1.000000

1.000000 2.000000 1.000000 1.000000

1.000000 3.000000 1.000000 1.000000

... continue

1.000000 40.000000 1.000000 1.000000

Page 142: Car Ride 2014

Adams/Car RideExample Output Hydromount Property File

162

Example Output Hydromount Property File The following is an example output hydromount property file. We left out the data for frequencies 4 - 39 Hz.

$-----------------------------------------------------MDI_HEADER [MDI_HEADER] FILE_TYPE = 'hbu' FILE_VERSION = 1.0 FILE_FORMAT = 'ASCII' $-----------------------------------------------------UNITS [UNITS] LENGTH = 'mm' FORCE = 'newton' ANGLE = 'degrees' MASS = 'kg' TIME = 'second' $-----------------------------------------------------GENERAL [GENERAL] DEFINITION = '.ride.attachment.ac_hydro_bushing' HYDRO_COORDINATE = 'z' BUSHING_PROPERTY_FILE = '<ride>/bushings.tbl/mdi_0001.bus' SUPER_IMPOSE_BUSHING = 'off' $----------------------------------------------------HYDRO_PARAMETERS [HYDRO_PARAMETERS] RUBBER_STIFFNESS = 406.544598 RUBBER_DAMPING = 0.29298822 COUPLING_STIFFNESS = 282.526692 COUPLING_STIFFNESS_DECLINING = 0.071232 LINEAR_FLUID_DAMPING = 1.10642663 QUADRATIC_FLUID_DAMPING = 0.01834762 EFFECTIVE_FLUID_MASS = 51.416425 CLEARANCE = 0.0 $----------------------------------------------------HYDRO_IDENTIFICATION_DATA [HYDRO_IDENTIFICATION_DATA]

{amplitude frequency cdyn phase}

0.100000 1.000000 404.863819 1.243071

0.100000 2.000000 399.691551 2.618614

0.100000 3.000000 388.455029 4.605679

... continue

0.100000 40.000000 713.285910 6.099968

0.500000 1.000000 404.772004 1.302907

0.500000 2.000000 399.309176 2.830528

0.500000 3.000000 389.903747 4.774778

... continue

0.500000 40.000000 716.810500 6.126563

Page 143: Car Ride 2014

163Dialog Box - F1 HelpExample Output Hydromount Property File

$----------------------------------------------------HYDRO_TEST_DATA [HYDRO_TEST_DATA]

$OBJECTIVE_FUNCTION = 1.5051 $INTEGRATOR_ERROR = 0.0050 $STEADY_STATE_ERROR = 0.0100 $CONVERGENCE_TOLERANCE = 0.0050 $*** OPTIMIZATION ABORDED ***

1.000000 1.000000 404.777324 1.347649

1.000000 2.000000 399.296585 3.024592

1.000000 3.000000 390.207932 5.272207

... continue

1.000000 40.000000 700.288389 6.281555

{amplitude frequency cdyn phase}

0.100000 1.000000 392.000000 1.900000

0.100000 2.000000 393.000000 3.800000

0.100000 3.000000 393.000000 4.800000

... continue

0.100000 40.000000 773.000000 4.700000

0.500000 1.000000 389.000000 2.800000

0.500000 2.000000 386.000000 4.100000

0.500000 3.000000 385.000000 5.800000

... continue

0.500000 40.000000 734.000000 4.800000

1.000000 1.000000 379.000000 3.100000

1.000000 2.000000 377.000000 4.800000

1.000000 3.000000 378.000000 6.900000

... continue

1.000000 40.000000 700.000000 4.700000

Page 144: Car Ride 2014

Adams/Car RideFull-Vehicle Analysis: ARIDE_FOUR_POST_TESTRIG

164

Full-Vehicle Analysis: ARIDE_FOUR_POST_TESTRIGRide -> Full-Vehicle Analysis -> Four-Post Test Rig

Sets up a full-vehicle analysis.

For the option: Do the following:

Full-Vehicle Assembly Select the full-vehicle assembly you want to analyze.

Tips on Entering File Names in Text Boxes.

Output Prefix Enter a string that specifies the Analysis Output Name. The string can contain only alphanumeric characters and underscores (_).

End Time Specify the time, in seconds, at which the analysis ends.

Mode of Simulation Select Interactive, Background, or Files_only.

Basis for Number of Output Steps

Select one of the following:

• number of output steps - Set the total number of outputs (per individual output variable). These will be equally spaced from time = zero to time = End Time.

• output interval - Set the time interval between outputs. Adams/Car Ride calculates the total number of outputs in terms of this number.

• output frequency - Set the time frequency at which outputs are stored. Adams/Car Ride calculates the total number of outputs in terms of this number. We give you this option because it is often easier to think in terms of frequency than in terms of the total number of outputs or the interval between outputs.

• min. number of outputs per input - This option applies only when you select a swept-sine input. Using this option will set the output frequency to be equal to the number you select in the Target Value For Basis text box multiplied by the highest frequency of the frequency sweep. This number should ideally range from ten to twenty, but never be less than six.

To prevent errors from aliasing, the frequency of outputs should be at least six times that of the highest input frequency that will affect outputs of interest. A factor of ten is much better, and a factor of 20 is very good.

Target Value for Basis Enter the number corresponding to your selection above for Basis for Number of Output Steps. The units for this text box change to reflect the selection you made above.

Page 145: Car Ride 2014

165Dialog Box - F1 HelpFull-Vehicle Analysis: ARIDE_FOUR_POST_TESTRIG

Note: The following four text boxes display values that describe the number of outputs in each of the options you can select in Basis for Number of Output Steps. Different information from the simulation set-up is needed to fill-in these text boxes. A value will appear in a text box as soon as you provide enough information for Adams/Car Ride to calculate its value. Note that these numbers might not be exactly the same as your selection in Target Value for Basis. This is because the values must be set so that an integral number of outputs is obtained.

Number of Output Steps See Note, above.

Output Interval See Note, above.

Output Frequency See Note, above.

The following text box is displayed only when you set Input Source to swept sine.

Min. Number of Output Steps Per Input

See Note, above.

Actuation Type Select one of the following:

• displacement

• velocity

• acceleration

• force

Your selection determines the type of control that prescribes the behavior of the test-rig actuators. Note that sometimes an actuation type either does not apply (that is, it doesn't make sense physically given the vehicle model) or is not supported depending on other settings you choose. For example, if you set Actuation Type to force, Adams/Car Ride automatically sets Input Locations to wheel spindles. This is because the other option for Input Locations, beneath tires, does not apply for Adams-compatible tire models that are supported in Adams/Car Ride. Because the tire carcass itself is not modeled as a physical body, a force cannot be applied to it.

For the option: Do the following:

Page 146: Car Ride 2014

Adams/Car RideFull-Vehicle Analysis: ARIDE_FOUR_POST_TESTRIG

166

Input Source Select one of the following:

• arbitrary solver functions

• road profiles

• swept sine

• RPC files

Your selection determines the type of control function that prescribes the behavior of the test-rig actuators with the selected Actuation Type. The selections depend on the Actuation Type. For example, of the four Actuation Types, you can always select arbitrary solver functions and swept sine as control functions. However, road profile inputs are only supported when Actuation Type is set to displacement.

Learn about RPC III Format

Input Locations Select one of the following:

• beneath tires - The actuators will excite the vehicle by contact with the tires.

• wheel spindles - The actuators will excite the vehicle by control directly at the wheel spindles.

If you set Actuation Type to force, only the wheel spindles option is applicable.

If you set Input Source to swept sine, Adams/Car Ride displays the following options:

Start Frequency Enter the frequency of the sinusoidal input at time = zero. The swept-sine input sweeps out the frequencies from Start Frequency to End Frequency linearly from time = zero to time = End Time. The Start Frequency can be higher than the End Frequency.

End Frequency Enter the frequency of the sinusoidal input at time = End Time. The swept-sine input sweeps out the frequencies from Start Frequency to End Frequency linearly from time = zero to time = End Time. The Start Frequency can be higher than the End Frequency.

The label on the following text box changes to reflect the selection you made for Actuation Type. For example, if you set it to acceleration, the label changes to Acceleration Amplitude.

Displacement Amplitude Select the amplitude of the sinusoidal control for the swept sine inputs. The name and units choices for this text box change to reflect your selection for Actuation Type.

For the option: Do the following:

Page 147: Car Ride 2014

Adams/Car RideFull-Vehicle Analysis: ARIDE_FOUR_POST_TESTRIG

167

Excitation Mode Your selection determines the relative phase of the test-rig actuators during a swept-sine simulation.

Select one of the following:

• heave - All actuators are in phase, thus causing a heave-type motion in the vehicle.

• pitch - The left and right actuators are in phase, but the rear actuators lag those of the front by 180 degrees, thus causing a pitch-type motion in the vehicle.

• roll - The front and rear actuators are in phase on each side of the vehicle, but the actuators on the right lag those on the left by 180 degrees, thus causing a roll-type motion in the vehicle.

• warp - The left-front and right-rear actuators are in phase. The right-front and left-rear actuators are also in phase, but they lag the left-front and right-rear actuators by 180 degrees, therefore causing a warp-type motion in the vehicle.

Active Actuators Specify which actuators are active during a swept-sine simulation. Inactive actuators remain stationary. The options depend on your selection for Excitation Mode. For example, if you set Excitation Mode to heave, you can set all actuators to be active, front or rear, right or left, or any particular one. However, if you set Excitation Mode to warp, all actuators must be active because a warp simulation has little meaning otherwise.

If you set Input Source to arbitrary solver functions, Adams/Car Ride displays the following options:

Note: Set each of the following text boxes to an Adams/Solver-function expression. You can enter the expression directly to create the function in the Function Builder. (When you exit the Function Builder, Adams/Car Ride automatically enters the expression you created into the appropriate text box.)

Enter 0 if:

• You want no motion of an actuator if the Actuation Type is kinematic.

• If you want the actuator to apply zero force at the spindle if you set Actuation Type to force. (In this case, the wheel associated with that actuator is not influenced by the test rig at all: it is free to fall.)

Left Front See Note, above.

Right Front See Note, above.

Left Rear See Note, above.

Right Rear See Note, above.

For the option: Do the following:

Page 148: Car Ride 2014

Adams/Car RideFull-Vehicle Analysis: ARIDE_FOUR_POST_TESTRIG

168

Solver Function Units Select the units for your Adams/Solver function expression.

The options have dimensions consistent with the setting in Actuation Type. Solver functions that you enter should return a numerical value expressed in the units of the Solver Function Units setting. For example, suppose the Actuation Type is set to acceleration and Solver Function Units is set to g's. Your solver functions should evaluate to a numerical value expressed in g's. This is true regardless of the setting in the Setting/Units menu in Adams/View.

If you set Input Source to road profiles, Adams/Car Ride displays the following option:

Set Up Road Profiles Select to display the dialog box Road-Profile Setup: ARIDE_FOUR_POST_TESTRIG, where you can set the road parameters.

Create Analysis Log File Select if you want Adams/Car to write information about the assembled model and analysis to an Analysis Log File.

Select to display a dialog box where you can add multi-line comments to any entity, to describe its purpose and function. Adams/Car Ride displays different comments dialog boxes, depending on the entity type for which you want to record comments:

• If recording comments for modeling entities in Standard Interface, Adams/Car Ride displays the Entity Comments dialog box.

• If recording comments for any other entity type, Adams/Car Ride displays the Modify Comment dialog box.

Learn more about Recording Comments.

For the option: Do the following:

Page 149: Car Ride 2014

169Dialog Box - F1 HelpFull-Vehicle Vibration Analysis: ARIDE_FOUR_POST_TESTRIG

Full-Vehicle Vibration Analysis: ARIDE_FOUR_POST_TESTRIGRide -> Full-Vehicle Vibration Analysis -> Four-Post Test Rig

Sets up a full-vehicle vibration analysis. To use this dialog box, you must have a license for Adams/Vibration. If you have access to the Adams/Vibration plugin, it loads when the Adams/Ride plugin loads.

For the option: Do the following:

Full-Vehicle Assembly Select the full-vehicle assembly you want to analyze.

Tips on Entering File Names in Text Boxes.

Output Prefix Enter a string that specifies the Analysis Output Name. The string can contain only alphanumeric characters and underscores (_).

Input Location Adams/Car Ride automatically creates vibration input channels. Depending on the actuation type chosen (below), the channels drive each pad of the rig with a kinematic input below each tire contact patch, to enable you to identify the vehicle response to road roughness inputs, or they drive wheel centers with a force input. At the same time, Adams/Car Ride automatically creates vibration output channels to enable you to analyze the response at key points on the vehicle, such as the wheel centers and strut (damper) top mounts. In addition, you can add vibration output channels to specific locations on your model.

Input Direction Adams/Car Ride creates vibration input channels (actuators) that act in the vertical direction (only).

Actuation Type Select the type of input the kinematic vibration actuators should provide in the test rig. As typical road spectra are approximately flat when plotted against velocity, we recommend the velocity input. However, the available options are:

• displacement

• velocity

• acceleration

• force

Page 150: Car Ride 2014

Adams/Car RideFull-Vehicle Vibration Analysis: ARIDE_FOUR_POST_TESTRIG

170

Actuator properties (for Left Front, Right Front, Left Rear, and Right Rear)

Specify the magnitude and phase (in degrees) of the input at each corner of the vehicle, in the units of the excitation quantities you selected for Actuation Type. By setting these values, you define the mode of excitation of the vehicle during the vibration analysis.

Select one of the following to define the actuators properties:

• Swept Sine. See Entering Swept Sine Function for available options.

• PSD. (Power Spectral Density). See Entering PSD Function for available options.

• User. (User-Defined Function). See Entering a User-Defined function for available options.

For example:

• If you choose swept sine excitational tire contact patches for all wheels, and set both front inputs to a magnitude of 1.0 and everything else to zero, you will excite the front axle only.

• If you set all magnitudes to 1.0, and the left channels to a phase of zero, but the right channels to a phase of 180 degrees, you will excite the vehicle with rolling motion that excites the left and right side with equal and opposite displacement or force (depending on whether you selected a kinematic or a force excitation above).

These values will have no influence on any transfer-function analyses, which present the output per unit input for every possible pair of input channel and output channel. The values will, however, influence frequency-response analyses, which present the system output that occurs because of the sum of all inputs (and the system transfer functions), considering both the phase and magnitude of those inputs.

Plot Actuator Select to open the Actuator Preview Plot dialog box where you can see the plot of your actuator without running a simulation.

Only available when modifying an input channel.

For the option: Do the following:

Page 151: Car Ride 2014

171Dialog Box - F1 HelpFull-Vehicle Vibration Analysis: A2N Export

Full-Vehicle Vibration Analysis: A2N Export Full-Vehicle A2N setup: Four Poster_Testrig

Sets up a full-vehicle A2N analysis. To use this dialog box, you must have a license for Adams/Vibration. If you have access to the Adams/Vibration plugin, it loads when the Adams/Car Ride plugin loads.

For the option: Do the following:

Full-Vehicle Assembly Select the full-vehicle assembly you want to analyze.

Analysis name Enter a string that specifies the Analysis Output Name. The string can contain only alphanumeric characters and underscores (_).

Input Location Adams/Car Ride automatically creates A2N input channels. Currently only Force is available as Actuation Type, so they are applied to drive wheel centers as a force input. At the same time, Adams/Car Ride automatically creates vibration output channels to enable you to analyze the response at key points on the vehicle, such as the wheel centers and strut (damper) top mounts. No other A2N output channels can currently be created in user specified locations on the model.

Input Direction Adams/Car Ride creates vibration input channels (actuators) that act in the vertical direction (only).

Page 152: Car Ride 2014

Adams/Car RideFull-Vehicle Vibration Analysis: A2N Export

172

Click on Ok button, the A2N MKB matrices export dialog box is displayed.

Actuation Type Select the type of input the actuators should provide in the test rig. Currently only one option is available:

• force

Actuator properties (for Left Front, Right Front, Left Rear, and Right Rear)

Specify the magnitude and phase (in degrees) of the input at each corner of the vehicle, in the units of the excitation quantities you selected for Actuation Type. By setting these values, you define the mode of excitation of the vehicle during the A2N analysis.

On the input channel an actuator force (swept-sine type) is applied into Nastran: each actuator is described by the direction (X, Y, Z), mode (translational = force or rotational = torque), force magnitude and phase angle

• Swept sine defines a constant amplitude sine function being applied to the model.

Due to the different marker orientation in correspondence of the wheel centers between left and right side (the forces are oriented as wheel center markers):

• If you choose swept sine for all wheels, and set both front inputs to a magnitude of 1.0 and everything else to zero, you will excite upward on the left side and downward on the right side - you will excite the vehicle with rolling motion that excites the left and right side with equal and opposite force

• If you set all magnitudes to 1.0, and the left channels to a phase of zero, but the right channels to a phase of 180 degrees, you will excite the full vehicle upward.

For the option: Do the following:

Page 153: Car Ride 2014

173Dialog Box - F1 HelpGSE Damper Code Import

GSE Damper Code Import

Modify GSE Damper dialog box -> select

Imports code for GSE Damper.

For the option: Do the following:

Library to be imported Enter the name of the RealTime Workshop (RTW) library you want to import. On Windows, this is likely to be a file with the extension .dll. On most Linux platforms, this file will have a .so extension, and on HP-UX it will have a .sl extension.

Adams/Car Ride copies this file from the specified location within your file system to the gse_damper.tbl directory of your default writable database.

Adams/Car Ride opens this file during the import process and analyzes it for parameters that you can change. It then writes these parameters to a property file as specified in the Property Files name text box.

Property file name Enter a new name for the property file Adams/Car Ride automatically generates when it imports the library. By default, Adams/Car Ride stores this property file in the gse_damper.tbl directory of your default writable database.

When you exit this dialog box, this text box will be automatically populated with the new property file.

Notes: • If the dialog box does not close when you select OK, select Cancel. This does not affect the importing of the library or the generation of the property file.

• At runtime, when Adams/Car Ride reads the property files, it copies the library to your home directory for use with Adams/Solver.

Page 154: Car Ride 2014

Adams/Car RideHydromount-Parameter Identification

174

Hydromount-Parameter IdentificationRide -> Tools -> Hydromount-Parameter Identification

Identifies the parameters of a hydromount model for given measurements of dynamic stiffness and loss angle dependent on frequency. Learn about Hydromount-Parameter Identification Tool.

For the option: Do the following:

Input File Name Enter the name of a hydromount input file. See About Input Hydromount Property Files.

Load Select to load an input file.

Input Parameters:

Calculate Frequency Response

Select to calculate the frequency response data with the current input parameters that are displayed in the text boxes. You can manually change those parameters and use this button to see the influence on the frequency response.

Error Control

Integrator Error Enter the allowed error of the states of the hydromount during numerical integration.

Steady-State Error Enter the allowed difference for the dynamic stiffness and loss angle between subsequent cycles.

Convergence Tolerance Enter the tolerance for which the objective function is considered converged.

Max Optimizer Loops Enter the maximum number of iterations to find the optimum.

Go Select to start the identification process.

Stop Select to stop the identification process.

Plot Displays the frequency response of the model, the dynamic stiffness in the plot named Cdyn and the loss angle in the plot named Phase.

Data Displays the input file and the frequency response data.

Output File Name -

Save Select to save an output file in property file format. See an Example Output Hydromount Property File.

Page 155: Car Ride 2014

175Dialog Box - F1 HelpISO Ride Index

ISO Ride IndexRide -> Full-Vehicle Analysis -> ISO Ride Index

Ride -> Full-Vehicle Vibration Analysis -> ISO Ride Index

Learn about the ISO Ride Index.

Define the parameters for ISO Ride Index.

For the option: Do the following:

Ride Index This is a read only field. Adams/Car Ride will display the calculated output Overall/Point Vibration Total Value here.

Output Select the appropriate output you want to calculate: OVTV, Feet PVTV, Seat PVTV and Back PVTV.

Analysis Select the appropriate analysis for calculating its Ride Index.

Depending on your output option selection, the following four tabs will be disabled or enabled. The Overall tab is enabled only for calculating OVTV output.

Define acceleration requests, scaling factors and ISO weighting curves (for driver/passenger Feet, Seat and Back locations)

• Specify the acceleration result set components for X, Y and Z directions at driver/passenger Feet, Seat and Back locations.

• Specify the directional and overall scaling factors for each of these location and direction.

• Specify the ISO frequency weighting curves for each of these locations and directions.

Page 156: Car Ride 2014

Adams/Car RideModify Frequency-Dependent Bushing

176

Modify Frequency-Dependent BushingRight-click component -> Modify

Learn About the Bushing Model.

For the option: Do the following:

Bushing Enter the database name of a hydro bushing.

Linear Preload Enter the initial translational force loading on the bushing, defined along the x-, y-, and z-axes of the bushing. The preload is always superimposed on the hydro force component.

Torsional Preload Enter the initial torsional force loading on the bushing, defined about the x-, y-, and z-axes of the bushing.

Linear Offset Enter the initial translational displacement of the bushing, defined along the x-, y-, and z-axes of the bushing.

Rotational Offset Enter the initial rotational displacement of the bushing, defined about the x-, y-, and z-axes of the bushing.

Property File Specify the property file that contains all static spline forces and all loss angles for the six force components.

When you modify component pairs (brothers), Adams/Car Ride enables the following option: (When you modify a single component, this option is disabled because a single component is by nature asymmetric.)

Symmetric Select one of the following:

• yes - Modify properties of both components in a pair.

• no - Only modify properties of the selected component.

Page 157: Car Ride 2014

177Dialog Box - F1 HelpModify Frequency-Dependent Bushing

Select to display a dialog box where you can add multi-line comments to any entity, to describe its purpose and function. Adams/Car Ride displays different comments dialog boxes, depending on the entity type for which you want to record comments:

• If recording comments for modeling entities in Standard Interface, Adams/Car Ride displays the Entity Comments dialog box.

• If recording comments for any other entity type, Adams/Car Ride displays the Modify Comment dialog box.

Learn more about Recording Comments. Select to view property file information. By default, your template-based

product displays this information in the Information window, but you can choose to display the information in a text editor.

Learn about:

• Working with the Information Window

• Editing Files Using a Text Editor

For the option: Do the following:

Page 158: Car Ride 2014

Adams/Car RideModify GSE Damper

178

Modify GSE DamperRight-click component -> Modify

Modifies a GSE Damper.

For the option: Do the following:

Damper Enter the database name of a GSE damper.

Property File Select the property file (See Property Files for more information) to be used or use the import utility

(see below).

Symmetric Select one of the following:

• yes - Modify properties of both components in a pair.

• no - Only modify properties of the selected component.

Select to display a dialog box where you can add multi-line comments to any entity, to describe its purpose and function. Adams/Car Ride displays different comments dialog boxes, depending on the entity type for which you want to record comments:

• If recording comments for modeling entities in Standard Interface, Adams/Car Ride displays the Entity Comments dialog box.

• If recording comments for any other entity type, Adams/Car Ride displays the Modify Comment dialog box.

Learn more about Recording Comments.

Select to display the GSE Damper Code Import dialog box.

Select to view property file information. By default, your template-based product displays this information in the Information window, but you can choose to display the information in a text editor.

Learn about:

• Working with the Information Window

• Editing Files Using a Text Editor

Page 159: Car Ride 2014

179Dialog Box - F1 HelpModify General Frequency Dependent Element

Modify General Frequency Dependent ElementDefine the parameters for a General FD Element

For the option: Do the following:

Bushing Enter the database name of a hydro bushing.

Property File Specify the property file that contains all static spline forces and all loss angles for the six force components.

Desired Components Select the desired components for which you want to modify the general frequency dependent element.

Type Select the appropriate type you want to modify:

Pfeffer Linear, Simple FD, Simple FD-Bushing, and General.

Preload Enter the initial translational force loading on the bushing, defined along the x-, y-, and z-axes of the bushing. The preload is always superimposed on the hydro force component.

Symmetric Select one of the following:

• yes - Modify properties of both components in a pair.

• no - Only modify properties of the selected component.

When you modify component pairs (brothers), Adams/Car Ride enables the following option: (When you modify a single component, this option is disabled because a single component is by nature asymmetric.)

Select to display a dialog box where you can add multi-line comments to any entity, to describe its purpose and function. Adams/Car Ride displays different comments dialog boxes, depending on the entity type for which you want to record comments:

• If recording comments for modeling entities in Standard Interface, Adams/Car Ride displays the Entity Comments dialog box.

• If recording comments for any other entity type, Adams/Car Ride displays the Modify Comment dialog box.

Learn more about Recording Comments.

Select to view property file information. By default, your template-based product displays this information in the Information window, but you can choose to display the information in a text editor.

Learn about:

• Working with the Information Window

• Editing Files Using a Text Editor

Page 160: Car Ride 2014

Adams/Car RideModify Hydro Bushing

180

Modify Hydro BushingRight-click component -> Modify

Modifies a hydro bushing. Learn more About Hydromount Models.

For the option: Do the following:

Bushing Enter the database name of a hydro bushing.

Orient using Select one of the following:

• Euler Angles

• Direction Vectors

If you select Euler Angles, Adams/Car Ride enables the following option:

Euler Angles Enter the three euler angle values that define the hydromount's orientation.

If you select Direction Vectors, Adams/Car Ride enables the following two options:

X Vector Enter the x, y, and z values that define the direction of the x-vector along which the hydromount will be oriented.

Z Vector Enter the x, y, and z values that define the direction of the z-vector along which the hydromount will be oriented.

Linear Preload Enter the initial translational force loading on the bushing, defined along the x-, y-, and z-axes of the bushing. The preload is always superimposed to the hydro force component.

Torsional Preload Enter the initial torsional force loading on the bushing, defined about the x-, y-, and z-axes of the bushing.

Linear Offset Enter the initial translational displacement of the bushing, defined along the x-, y-, and z-axes of the bushing. The displacement offset dz0 in the hydro_force is copied from this linear offset.

Rotational Offset Enter the initial rotational displacement of the bushing, defined about the x-, y-, and z-axes of the bushing.

Property File Specify the property file that contains the hydro force parameter and the name of the bushing property file.

Symmetric Enabled when you modify component pairs (or brothers):

• yes - Modify properties of both components in a pair.

• no - Only modify properties of the selected component.

When you modify a single component, this option is disabled because a single component is by nature assymetric.

Page 161: Car Ride 2014

181Dialog Box - F1 HelpModify Hydro Bushing

Property File Select to view property file information. By default, your template-based product displays this information in the Information window, but you can choose to display the information in a text editor.

Learn about:

• Working with the Information Window

• Editing Files Using a Text Editor

Apply Property File Select to cause the UDE instance to match the property file. (Adams/Car Ride automatically performs this operation before a simulation.)

Bushing Property Select to view property file information. By default, your template-based product displays this information in the Information window, but you can choose to display the information in a text editor.

Learn about:

• Working with the Information Window

• Editing Files Using a Text Editor

Superimpose Bushing Select to switch the superimposition of the bushing force component on or off.

Select to display a dialog box where you can add multi-line comments to any entity, to describe its purpose and function. Adams/Car Ride displays different comments dialog boxes, depending on the entity type for which you want to record comments:

• If recording comments for modeling entities in Standard Interface, Adams/Car Ride displays the Entity Comments dialog box.

• If recording comments for any other entity type, Adams/Car Ride displays the Modify Comment dialog box.

Learn more about Recording Comments.

For the option: Do the following:

Page 162: Car Ride 2014

Adams/Car RideModify Single Component Frequency Dependent Element

182

Modify Single Component Frequency Dependent ElementDefine the parameters for a Single Component FD Element

For the option: Do the following

Single component FD element

Enter the database name of a hydro bushing.

Property File Specify the property file that contains all static spline forces and all loss angles for the force component.

Type Select the appropriate type you want to modify:

Pfeffer Linear, Simple FD, Simple FD-Bushing, and General.

Preload Enter the initial translational force loading on the bushing, defined along the x-, y-, and z-axes of the bushing. The preload is always superimposed on the hydro force component.

Symmetric Select one of the following:

• yes - Modify properties of both components in a pair.

• no - Only modify properties of the selected component.

When you modify component pairs (brothers), Adams/Car Ride enables the following option: (When you modify a single component, this option is disabled because a single component is by nature asymmetric.)

Select to display a dialog box where you can add multi-line comments to any entity, to describe its purpose and function. Adams/Car Ride displays different comments dialog boxes, depending on the entity type for which you want to record comments:

• If recording comments for modeling entities in Standard Interface, Adams/Car Ride displays the Entity Comments dialog box.

• If recording comments for any other entity type, Adams/Car Ride displays the Modify Comment dialog box.

Learn more about Recording Comments.

Select to view property file information. By default, your template-based product displays this information in the Information window, but you can choose to display the information in a text editor.

Learn about:

• Working with the Information Window

• Editing Files Using a Text Editor

Page 163: Car Ride 2014

183Dialog Box - F1 HelpPerform Vibration Analysis

Perform Vibration AnalysisRide -> Full-Vehicle Vibration Analysis -> Four-Post Test Rig -> OK

Sets up a vibration full-vehicle analysis. To use this dialog box, you must have a license for Adams/Vibration. If you have access to the Adams/Vibration plugin, then it will have been loaded when the Adams/Ride plugin was loaded.

For the option: Do the following:

Tips on Entering File Names in Text Boxes

New Vibration Analysis/Vibration Analysis

Specify whether you are creating a new analysis or running an existing one.

Operating Point Generate the operating point for the analysis by using a simulation script.

Simulation Script Name Select a simulation script that configures the model and test rig for the vibration analysis.

Input Channels Specify which input (and actuators) and output channels should be active during the analysis. Note that if you select N input channels and M output channels, then N*M transfer functions will be generated.

The remainder of the options available in this dialog box are described in the help for the Adams/Vibration Perform Vibration Analysis dialog box.

Page 164: Car Ride 2014

Adams/Car RideRoad-Profile Generation

184

Road-Profile GenerationRide -> Tools -> Road-Profile Generation

Generates a road profile using the Sayers (see References) model. Learn about Road-Profile Generation Tool.

For the option: Do the following:

See Parameter Variables for Sayers Roughness Model.

Elevation PSD Parameter: Ge Enter a value for the Ge parameter.

Velocity PSD Parameter: Gs Enter a value for the Gs parameter.

Acceleration PSD Parameter: Ga Enter a value for the Ga parameter.

Profile Length Enter the length of the road whose profile you want the model to approximate.

Sample Interval Enter the distance between profile data points. Sample interval is the same as the absolute value of the difference in the Station of two adjacent data points.

Correlation Baselength Enter the quantity LB (used in Equation (3)).

Output Filename For RPC III File

Enter the full path to a file that Adams/Car Ride will create to store the profile data. Adams/Car Ride stores the data in the RPC III file format (Learn about RPC III Format). This is a binary file format developed by MTS [4]. The file will contain two channels: channels 1 and 2, which will contain the profile data for the left and right wheeltracks, respectively. The independent variable of the file is station, measured in meters (m). The two dependent variables (channels 1 and 2) are road elevation, measured in millimeters (mm).

Tips on Entering File Names in Text Boxes.

After you create the RPC file, you can view it in Adams/PostProcessor. To do so, go to Adams/PostProcessor (F8), select File -> Import -> RPC File, and then select the file you created. Plot the two channels: LElev and RElev. Note that the y-axis will be labeled mm, but the x-axis will be labeled No Units. The actual units are meters (m), but, currently the RPC III file format doesn't provide a way to store this information, so there is nothing in the file that Adams/PostProcessor could use to create the units label for the x-axis.

The following channel names appear in Adams/PostProcessor, when you import the file and plot it. Normally, however, you access the RPC III files by referring to channel numbers rather than channel names.

Page 165: Car Ride 2014

185Dialog Box - F1 HelpRoad-Profile Generation

Channel Name for Left Wheeltrack

Enter a name for channel 1.

Channel Name for Right Wheeltrack

Enter a name for channel 2.

Seed For Random Numbers Enter an integer that determines how the random-number generator (used for creating a Gaussian distribution for the Sayers model) is seeded.

• If the seed is negative, for example, -1, Adams/Car Ride uses the computer's clock as a seed. Therefore, multiple RPC III files created for the same set of profile parameters will be different. An infinite number of profiles can be generated to match the same set of Sayers-model parameters.

• If the seed is greater than zero, Adams/Car Ride uses the value of the seed as the seed to the random-number generator. Therefore, each RPC III file created for the same set of parameters, and the same seed, will be identical. This, then, is a means of generating reproducible profiles with the Sayers model.

For the option: Do the following:

Page 166: Car Ride 2014

Adams/Car RideRoad-Profile Setup: ARIDE_FOUR_POST_TESTRIG

186

Road-Profile Setup: ARIDE_FOUR_POST_TESTRIGRide -> Full-Vehicle Analysis -> Four-Post Test Rig -> Set Up Road Profiles

Sets up the road profile (See Road-Profile Generation Tool).

For the option: Do the following:

Profile Source Select one of the following:

• RPC files - Allows you to use road-profile data stored in the RPC III file format to drive the four-post test-rig actuators in displacement. Such data could be measured (for example, from a profilometer) or generated from a mathematical model for road roughness. In particular, Ride -> Tools -> Road-Profile Generation displays a dialog box for such a mathematical model. The data generated is stored in the RPC III format. Therefore, you can use that tool to generate data to select from the current dialog box. Learn about RPC III Format.

• sum RPC files & table functions - Takes the height road-profile data from both sources and sums it together as the input to the actuators. Therefore, is useful if you want to superimpose a bump on top of a road profile. For example, you might represent the overall road with data from RPC files, but then create a bump with a table function.

• table functions - Allows you to drive the actuators in displacement using a table function whose data is stored in a TeimOrbit file (see TeimOrbit File Format). You can create and edit such tables with the Curve Manager. (For Beta, we recommend that you use the example table-function data file as templates to create your own data by directly editing the files, instead of the Curve Manager.)

See Curve Manager.

Vehicle Speed Select the forward speed of travel for the vehicle. Note that negative values are not allowed.

The vehicle does not travel down a road with the four-post test rig: the wheels do not spin and the mass-center velocity hovers around zero. However, the vertical-height inputs to the rear wheels lag behind those of the front wheels by (Calculated Time Lag) = (Calculated Wheelbase)/(Vehicle Speed). Therefore, the test rig cam approximates a road very well.

Calculated Wheelbase Displays the calculated wheelbase. The wheelbase is derived from the locations of the spindle-centers in the vehicle assembly. It is the average of the for-aft distance for the left and right side of the vehicle, evaluated in the design configuration (not in the static-equilibrium configuration).

Page 167: Car Ride 2014

187Dialog Box - F1 HelpRoad-Profile Setup: ARIDE_FOUR_POST_TESTRIG

Calculated Time Lag Displays the time that inputs to the rear wheels lag behind those of the front. It is calculated as explained for Vehicle Speed.

If you set Profile Source to RPC files, Adams/Car Ride displays the following options:

RPC Files With Road Profiles - Left Wheeltrack Profile/Right Wheeltrack Profile

File Name Select the full path to an RPC III file with road-profile data. If you right-click and Search the <aride_shared> database, you will see at least two RPC III files in the "road_profiles.tbl" directory: "example.rsp" and "flat.rsp". Note that .rsp is the extension that denotes RPC files.

Use flat.rsp if you want zero vertical input to one (or both) sides of the vehicle. Both the left and right wheeltracks can refer to the same RPC file, but they can also refer to different files.

Channel Number Enter the number of the channel that has the data you want to use. Data is stored in RPC III files by channel. Each channel is referenced by its number. Both the left and right wheeltracks can use the same channel from the same file, different channels from the same file, or the same channel or different channels (numbers) from different files.

You can give the vehicle symmetric inputs if you use the same channel number from the same file for both wheeltracks. Note that the Adams/Car Ride Road-Profile Generation tool always uses channel 1 for the left wheeltrack and channel 2 for the right wheeltrack.

If you set Profile Source to sum RPC files & table functions or to table functions, Adams/Car Ride displays the following options:

Table-Function Property Files With Road Profiles - Left Wheeltrack Profile/Right Wheeltrack Profile

File Name Select the full path to a TeimOrbit text file with road-profile data. If you right-click and Search the <aride_shared> database, you will see at least two RPC III files in the "road_profiles.tbl" directory: "bump_1inch.rpt" and "flat.rpt". Note that .rpt is the extension that denotes TeimOrbit road-profile data files.).

Use flat.rpt if you want zero vertical input to one (or both) sides of the vehicle. Both the left and right wheeltracks can refer to the same TeimOrbit file, but they can also refer to different files. You can give the vehicle symmetric inputs if you use the same file for both wheeltracks.

Select to display the Data Editor/Viewer to plot the wheeltrack profile.

For the option: Do the following:

Page 168: Car Ride 2014

Adams/Car RideRoad-Profile Setup: ARIDE_FOUR_POST_TESTRIG

188

Page 169: Car Ride 2014

183Appendix

Appendix

Page 170: Car Ride 2014

Adams/Car RideConvergence Tolerance

184

Convergence ToleranceConvergence tolerance is the tolerance that determines when the objective function has converged. The optimization stops when this tolerance is met. Specifically, the convergence tolerance is satisfied if:

(convergence tolerance) > (error_dynamic_stiffness + error_loss_angle)*100/number_of_frequencies

where

error_dynamic_stiffness = Sqrt(Sum_of_all((stiffness_calculated - stiffness_measured)**2))/stiffness_measured_middle

and

error_loss_angle = Sqrt(Sum_of_all((loss_angle_calculated - loss_angle_measured)**2))/loss_angle_middle_measured)

Page 171: Car Ride 2014

185AppendixDamper Sweep

Damper Sweep

Page 172: Car Ride 2014

Adams/Car RideExample Input Hydromount Property File

186

Example Input Hydromount Property FileThe following is a sample input hydromount property file (extension .hbu). This sample file contains the minimum set of required data.

Learn About Input Hydromount Property Files.

$-----------------------------------------------------------MDI_HEADER[MDI_HEADER] FILE_TYPE = 'hbu' FILE_VERSION = 1.0 FILE_FORMAT = 'ASCII'$----------------------------------------------------------------UNITS [UNITS] LENGTH = 'mm' FORCE = 'newton' ANGLE = 'degrees' MASS = 'kg' TIME = 'second' $--------------------------------------------------------------GENERAL [GENERAL] DEFINITION = '.ride.attachment.ac_hydro_bushing' HYDRO_COORDINATE = 'z' BUSHING_PROPERTY_FILE = '<ride>/bushings.tbl/mdi_0001.bus' SUPER_IMPOSE_BUSHING = 'off' $----------------------------HYDRO_TEST_DATA [HYDRO_TEST_DATA]

{amplitude frequency cdyn phase}

0.100000 5.000000 620.0 7.7

0.100000 8.000000 652.0 16.2

0.100000 10.000000 776.0 20.4

0.100000 12.000000 911.0 20.2

0.100000 15.000000 1038.0 12.9

0.100000 20.000000 963.0 5.5

0.100000 25.000000 902.0 4.0

0.100000 30.000000 881.0 4.3

0.100000 40.000000 841.0 5.3

0.100000 50.000000v 838.0 6.6

0.800000 5.000000 620.0 9.9

0.800000 8.000000 620.0 20.9

0.800000 10.000000 691.0 29.1

0.800000 12.000000 855.0 32.4

Page 173: Car Ride 2014

187AppendixExample Input Hydromount Property File

0.800000 15.000000 1085.0 25.2

0.800000 20.000000 1142.0 12.0

0.800000 25.000000 1100.0 7.0

0.800000 30.000000 1068.0 5.4

0.800000 40.000000 1020.0 5.3

0.800000 50.000000 1031.0 5.6

Page 174: Car Ride 2014

Adams/Car RideForce vs Displacement for Linear Damper

188

Force vs Displacement for Linear Damper

Page 175: Car Ride 2014

189AppendixFourier Method

Fourier Method a0 = Integral(2*sweep_frequency*fx) a1 = Integral(2*sweep_frequency*cos(2*pi*sweep_frequency*time)*fx) b1 = Integral(2*sweep_frequency*sin(2*pi*sweep_frequency*time)*fx) loss_angle = atan(a1/b1) f_ampl = a1 /sin(loss_angle) f_min = a0/2 - f_ampl f_max = a0/2 + f_ampl loss_energy = a1 * f_ampl * PI

Page 176: Car Ride 2014

Adams/Car RideIntegrator Error

190

Integrator Error Integrator error is the allowed error of the state variables of the hydromount during numerical integration. The state variables are the displacement (mm) and velocity (mm/s) of the effective fluid mass. The same numerical value, specified in the Integrator Error text box, is used for both states.

The numerical integration is done with a 4th-order Runge-Kutta method. The time-step size is automatically varied during the integration in accord with the value of the error tolerance. The error is calculated based on two means of computing the next values of the state variables: one explicit and the other implicit. If the results of the explicit and implicit computations differ by more than the error tolerance for either state variable, then the time-step size is decreased and the integrator tries again. If the error is very small compared to the error tolerance for both state variables, then the time-step size is increased for the next time interval.

Page 177: Car Ride 2014

191AppendixMax Optimizer Loops

Max Optimizer Loops Max optimizer loops is the maximum number of iterations the optimizer is allowed to perform to satisfy the convergence tolerance. The optimizer will stop after this number of iterations have been performed even if the convergence tolerance is not satisfied.

One iteration constitutes the calculation of a pair of dynamic stiffness and loss angle values for each amplitude and frequency of the measured data. The progress bar shows the percentage of the pairs of calculated values that have so far been obtained for a single iteration.

Page 178: Car Ride 2014

Adams/Car RideMin-Max Method

192

Min-Max Method

Fmin and Fmax are measured at velocity = 0.

Dynamic stiffness CDYN = (Fmax - Fmin)/(2*amplitude)

Strain energy W = (Fmax - Fmin)*amplitude/4

Loss energy dW = abs(Integral(F(t)*vel(t) dt)) in the interval [(i-1)*2pi , i*2pi]

Relative damping PSI = dW / W

Loss angle PHI = asin( PSI / (2*pi) )

Page 179: Car Ride 2014

193AppendixPhase

Phase

Page 180: Car Ride 2014

Adams/Car RidePhase 2

194

Phase 2

Page 181: Car Ride 2014

195AppendixResults with 1 mm amplitude and 5 Hz

Results with 1 mm amplitude and 5 Hz

Page 182: Car Ride 2014

Adams/Car RideSawtooth

196

Sawtooth

Page 183: Car Ride 2014

197AppendixStation

StationStation is the projection of the absolute arc-length in 3D space of the road centerline, from some reference point to a point of interest, projected into the global x-y plane.

Page 184: Car Ride 2014

Adams/Car RideSteady-State Error

198

Steady-State Error Steady-state error is the allowed difference for the dynamic stiffness and loss angle between two consecutive cycles of the sinusoidal excitation. The computations for a particular frequency of excitation terminate when the calculated error is less than the tolerance.

The steady-state error tolerance is dimensionless. Specifically, the error tolerance is satisfied if, for two consecutive cycles of the sinusoidal excitation:

error_dynamic_stiffness < (steady-state error)

and

error_loss_angle < (steady-state error)

where,

error_dynamic_stiffness =Max(stiffness_calculated(amplitude_1)/stiffness_max_measured(amplitude_1),...,stiffness_calculated(amplitude_n)/stiffness_max_measured(amplitude_n))

error_loss_angle =Max(loss_angle_calculated(amplitude_1)/loss_angle_max_measured(amplitude_1),...,loss_angle_calculated(amplitude_n)/loss_angle_max_measured(amplitude_n))

and the stiffness and cdyn and loss angle are calculated over one sinusoid cycle.

The steady state error indicates when the system is considered to be in steady state condition. This is used to shorten the overall CPU time.

Page 185: Car Ride 2014

151

AAdams/Car Ride

benefits of using 2starting 3tasks you can do with 2tools for calculations 57

Adams-to-Nastranabout exporting 58export dialog box 78ouput files 59procedure 60

ADM2NAS, about 58Analyses

about 4component 4full vehicle 5full vehicle vibration 5

BBushing

example input property file 96example output property file 100parameter identification dialog box 81

CComponent analysis

frequency sweep 82set up test rig 88

Component test rig 90Components

about 13frequency bushing 23general bushing 27general frequency dependent 14GSE damper 32hydromount 47single-component frequency dependent 20

EExample

input bushing property file 96input hydromount propery file 53

Page 186: Car Ride 2014

Adams/Vibration152

output bushing property file 100output hydromount property file 54

Exporting Adams to Nastran 58Exporting RTW model to Adams/Car Ride 42FFrequency sweep component analysis 82Frequency-dependent bushing

about 23, 27modify 119

Frequency-dependent elementgeneral 14single-component 20

Full-vehicle analysesabout 5dialog box 107

GGenerating road profile

about 70dialog box 127introducing 70parameter values 71references 72

GSE damperabout 32creating 34functions 34importing code for 116modifying 121replacing 41Simulink example 36

HHydro bushing 123Hydromount

about 47calculating frequency response 66example input propery file 53example output property file 54identification process 65introducing tool 61

Page 187: Car Ride 2014

153

launching tool 66models 61parameter identification dialog box 117

MModifying

frequency-dependent bushing 119GSE damper 121hydro bushing 123

OOutput files, Adams-to-Nastran 59Output hydromount property file example 54RRoad profile

generating 72generating, dialog box 127generation tool overview 70introducing generation tool 70setting up 129

RPC files 129RTW model, exporting to Adams/Car Ride 42SSetting up

full-vehicle analysis 107road profile 129test rig component analysis 82vibration full-vehicle analysis 107

Simulink RTW model, exporting to Adams/Car Ride 42Simulink, GSE damper in 36Starting Adams/Car Ride 3VVibration full-vehicle analyses

dialog box 107performing 112

Page 188: Car Ride 2014

Adams/Vibration154


Recommended