A FEM BASED ANALYSIS AND MODIFICATION OF A COMPOSITE AUTOMOBILE DRIVE SHAFT

7/22/2019 A FEM BASED ANALYSIS AND MODIFICATION OF A COMPOSITE AUTOMOBILE DRIVE SHAFT

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A FEM BASED ANALYSIS ANDMODIFICATION OF A COMPOSITE

AUTOMOBILE DRIVE SHAFT

Presented by: Guided by:

Narendra Kumar Gajpal Mr.Benedict Thomas

M.Tech 4thSemester Associate Professor

(Roll No.5115809005) CCET,Bhilai


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Objectiveof this thesis

In this thesis a study has been performed first to validate the

fact that composite drive shaft possess higher Torsional

Stress Bearing Capacity and Natural frequency which is

actually desired. And find the properties of composite

material with use of mat lab

To validate the above objective an international paper has

been reproduced with help of MATLAB and ANSYS 12.0.

Then a modification has been done on the design of the

shaft by changing its longitudinal profile.

A study has been conducted on its natural frequency and

torsional capacity for different profile dimensions and shape.


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LITERATUREREVIEW

Efficiency enhancement of any car as a whole has become thebiggest challenge in the field of Automobile Engineering in this

century. The reason behind this is the continuous contraction of

fossil fuel resource.

To increase the efficiency of a car, so many steps may be

taken as , enhancement of engine efficiency, decreasing of car body weight,

efficient design of car body to use the aerodynamics and

reduction of losses in power transmission.

Many researches are going on in each option.

In this paper a research has been done on drive shaft design

used in power transmission of a car.


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Contd

In this work a drive shaft of dimensions as

mentioned in the work of Sanjay Gummandi et al [9] has been

considered. In their work Sanjay Gummandi et al [9] tested a

drive shaft under a torsion load and they considered three

types of material, one isotropic and three Compositematerials.

Isotropic material they considered is Steel (SM45C) and three

Composite materials which are orthotropic in nature are- E-

Glass/Epoxy, HS Carbon/Epoxy and HM Carbon/Epoxy. In

year of 1998


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Contd

Fredrik Cato & Magnus Taskinen did a remarkable work on Noise andVibration Investigation of Composite Shaft [1]).

In same year S.Rajendran and D.Q.Song did a work on compositepanel and investigated its buckling capacity [2].

A meritorious work was done by Murat Ocalan in the year of 2002 onHigh flexibility rotorcraft drive shaft using flexible matrix composites and

active bearing control [3].

Tomas Zackrisson did a remarkable work on automatic gearboxdriveline made of composite material in the year of 2003.

David B. Adamss work on optimization of staking sequence of

composite material in the year of 2005 is mentionable [6].

In the year of 2007Yeow Ng & Al Kumnick did a work on Cross-PlyLaminate Stacking Sequence for The Compression Strength Testing of Aunidirectional Boron EPOXY material . [7]


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Contd.. In the same year Duncan J. Lawrie did a work on

Development of a High Torque Density, Flexible, CompositeDriveshaft [10]).

A work on Design Analysis of an Automotive Composite DriveShaft by M.A.K. Chowdhuri and R.A. Hossain was done inthe year of 2010.

Besides above mentioned papers and thesis few articles andtutorials have also been referred. Mechanics of CompositeMaterials with MATLAB , by Prof. George Z. Voyiadjis &Prof. Peter I. Kattan (Springer Publication) gives a detaileddiscussion about the methodology of solving compositemechanics equations using MATLAB.

From a book written by Robert M. Jones on compositemechanics as titled Mechanics of Composite Materials,Taylor & Francis, 2ndEdition, a detailed concept andinformation about composite material have been incurred. Inthis work help has also been taken from ANSYSDocumentation


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Introduction

Composite Materials:

Composites consist of two or more materials or materialphases that are combined to produce a material that hassuperior properties to those of its individual constituents.

The constituents are combined at a macroscopic level and ornot soluble in each other.

The main difference between composite and an alloy areconstituent materials which are insoluble in each other andthe individual constituents retain those properties in the case

of composites, where as in alloys, constituent materials aresoluble in each other and forms a new material which hasdifferent properties from their constituents.


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Advantages of Composites

The advantages of composites over the conventional

materials are:

High strength to weight ratio

High stiffness to weight ratio

High impact resistance

Better fatigue resistance

Improved corrosion resistance Good thermal conductivity

The limitations of composites are:

Mechanical characterization of a composite structure is more

complex than that of a metallic structure

The design of fiber reinforced structure is difficult compared

to a metallic structure, mainly due to the difference in

properties in directions

The fabrication cost of composites is high

Rework and repairing are difficult


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Applications of Composites

Automotive: Drive shafts, clutch plates, engine blocks, pushrods, frames, Valve guides, automotive racing brakes, filament

wound fuel tanks, fiber Glass/Epoxy leaf springs for heavy trucksand trailers, rocker arm covers, suspension arms and bearingsfor steering system, bumpers, body panels and doors

Aircraft: Drive shafts, rudders, elevators, bearings, landing geardoors, panels and floorings of airplanes etc.

Space: payload bay doors, remote manipulator arm, high gain

antenna, antenna ribs and struts etc. Marine: Propeller vanes, fans & blowers, gear cases, valves

&strainers, condenser shells.

Chemical Industries: Composite vessels for liquid natural gasfor alternative fuel vehicle, racked bottles for fire service,mountain climbing, underground storage tanks, ducts and stacks

etc. Electrical & Electronics: Structures for overhead transmission

lines for railways, Power line insulators, Lighting poles, Fiberoptics tensile members etc.

Sports Goods: Tennis rackets, Golf club shafts, Fishing rods,Bicycle framework, Hockey sticks, Surfboards, Helmets andothers.


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About drive shaft

The torque that is produced from the engine and transmissionmust be transferred to the rear wheels to push the vehicle

forward and reverse. The drive shaft must provide a smooth, uninterrupted flow of

power to the axles. The drive shaft and differential are used totransfer this torque.

Function of drive shaft are

First, it must transmit torque from the transmission to thedifferential gear box.

During the operation, it is necessary to transmit maximum low-gear torque developed by the engine.

The drive shafts must also be capable of rotating at the very fastspeeds required by the vehicle.

The drive shaft must also operate through constantly changingangles between the transmission, the differential and the axles.

As the rear wheels roll over bumps in the road, the differentialand axles move up and down. This movement changes the anglebetween the transmission and the differential.


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Different type of shaft

Transmission shaft:

These shafts transmit power between the source and the

machines absorbing power.Machine Shaft: These shafts form an integral part of the

machine itself.

Axle: A shaft is called "an axle", if it is a stationary machine

element and is used for the transmission of bending moment

only. It simply acts as a support for rotating bodies. Spindle: A shaft is called "a spindle", if it is a short shaft that

imparts motion either to a cutting tool or to a work-piece.

Automobile Drive Shaft: Transmits power from main gearbox

to differential gear box.

Ship Propeller Shaft: Transmits power from gearbox topropeller attached on it.

Helicopter Tail Rotor Shaft: Transmits power to rail rotor fan.

This list has no end, since in every machine, gearboxes,

automobiles etc. shafts are there to transmit power from one end

to other.


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Design of a Composite Drive Shaft


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Design specifications & Assumptions

Design specifications

The fundamental natural speed - 6,500 rpm to avoid whirling

vibration and the torque transmission capability of the drive

shaft should be larger than 3,500 Nm.

The drive shaft outer diameter should not exceed 100 mm

due to space limitations. Here outer diameter of the shaft is

taken as 90 mm.

The drive shaft of transmission system is to be designed

optimally for above specified design requirement.

Assumptions

The shaft rotates at a constant speed about its longitudinal

axis. The shaft has a uniform, circular cross section.

The shaft is perfectly balanced, i.e., at every cross section,

the mass center coincides with the geometric center.


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Selection of Cross-Section & Selection of Materials

The drive shaft can be solid circular or hollow circular. Herehollow circular cross-section was chosen because:

The hollow circular shafts are stronger in per kg weight thansolid circular.

The stress distribution in case of solid shaft is zero at the centerand maximum at the outer surface while in hollow shaft stressvariation is smaller. In solid shafts the material close to thecenter are not fully utilized.

Material

The important considerations in selecting material are cost,temperature capability, elongation to failure and resistance toimpact (a function of modulus of elongation). The materialselected for most of the drive shafts are either epoxies or vinyl

esters. Here, epoxy resin material was selected due to its highstrength, good wetting of fibers, lower curing shrinkage, andbetter dimensional stability

Based on the advantages discussed earlier, the E-Glass/Epoxy,High Strength Carbon/Epoxy materials are selected for

composite drive shaft.


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Properties of High Strength Carbon/Epoxy

S1.No property UnitsHS

Carbon/Epoxy

1. E11 GpaLongitudinal elastic modules of

lamina134.0

2. E22 Gpa

Transverse elastic modules of

lamina 7.0

3. G12 GpaShear modules of lamina in 12

direction5.8

4. 12 -Major Poisson ratio

0.3

5. St1= Sc1 Mpa

Ultimate longitudinal tensile and

compressive strength

880.0

6. St2= Sc2 Mpa

Ultimate transverse tensile and

compressive strength60.0

7. S12 MpaUltimate in plane shear strength

97.0

8. Kg/m3

Density of shaft material

1600.0


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FEA MODEL OF A UNIFORM COMPOSITE DRIVE SHAFT

In this work a uniform composite drive shaft of followingdimensions has been modeled in ANSYS with composite

element SOLID46.

Then the FEA model has been tested statically under a

torque load to examine its deflection and Von-misses stress

distribution. It has also been tested or simulated in ANSYS to determine

natural frequencies of 1st, 2ndand 3rdmode.

Before FEA model development of uniform drive shaft with

composite element, a detail discussion has been taken place

about the behavior of a composite material


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Geometry and parameters of the uniform drive shaft made of

composite material

A drive shaft of OD 90mm and thickness 2.04 mm has beenconsidered for analysis. Length of the drive shaft is 1250mm.

It is made out of a composite material High Strength Carbon/

Epoxy. Property of the HS Carbon/Epoxy has been presented

above .

Mechanical properties of each lamina of composite The composite drive shaft has been made with 17 layer each

of having thickness 0.12mm and stacking sequence

[-56/-51/74/-82/67/70/13/-44/-75]s.

After putting the value of E11, E22, G12 and 12 in MATLAB

program shown in appendix A we get lamina-wise mechanicalproperties have been shown.


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Mechanical property of whole lamina

Exy (GPa) Exz (GPa) Eyz (GPa) xy yz zx Gxy(GPa)

Gxz

(GPa)Gyz

(GPa)26.6893 71.6799 71.6799 0.2090 0 0 20.0170 20.0170 20.0170


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Modeling of composite drive shaft in ANSYS.

Modeling and Meshing of composite drive shafthave been done through an ANSYS APDL

programming which has been produced in

appendix C. Meshed model of uniform composite

driveshaft as per the ANSYS APDL program has

been shown below


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Meshed model of composite drive shaft


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Meshed model of composite drive shaft showing 17 layers


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Boundary Conditions and Loading

Here investigation has been done on composite drive shaft

made of High strength Carbon/ Epoxy which has been

imposed of torque 3500Nm To impose torque on each nodes of drive shaft FEA model

MASS-21 element has been introduced. Figure bellow

depicts the Boundary Conditions and Loading of composite

drive shaft


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Static analysis of the shaft

Shaft has been fixed with all boundary conditions zero at oneend and torque 3500Nm has been imposed on the other end.

After imposing boundary conditions and loading model has

been solved for the static loading.

After solution rotational deflection(0.102337mm) has beenchecked which agree with the result of Sanjay et. al. [9].

Deflection result of work (0.103686mm) has been shown

below.


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Torsional deflection 0.103686mm mm about axis of

composite shaft as per this work.


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Von-Mises stress

As it has been mentioned above that layered composite driveshaft has yield strength 440 MPa so the Von-Mises stress

should come below 440 MPa. Figure below shows the Von-

Mises stress distribution of composite drive shaft.

As per the figure it is clear that equivalent stress or Von-

Mises stress is 350.927 MPa which is well below the value of

yield strength (440 MPa) after imposing the limiting torque

value of 3500 Nm. So the model of composite drive shaft has

been validated.


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Von-Mises stress is 350.927 Mpa as per this work


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Modal analysis of the shaft

Another analysis has been done on this composite drive shaftis the Modal analysis. By this analysis natural frequency of

the shaft has been found out up to three modes.

Below are the figures for 1st, 2ndand 3rdmode vibration

Frequencies of the composite drive shaft at different modes of

vibration.It is clear from the above figures that the drive shaft will

collapse on 3rdmode of vibration.

Set Time /

frequency

Load step Substeps cumulative

1 12.053 Hz 1 1 1

2 12.053 Hz 1 2 2


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1stmode vibration


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2ndmode vibration.


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3rdmode vibration


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DESIGN MODIFICATIONS ADOPTED

Behind this idea the main reason is that a taper beam alwaysexhibits lower stress than a uniform beam. To perform the

static and modal analysis of a taper beam two taper angles

have been taken. These two angles are 1 and 1.5.

Geometry of a tapered drive shaft having taper angle 1

shown in ANSYS


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. After generating geometry and meshing it in ANSYS, it has

been simulated for a torque of 3500 Nm. Material used for

this drive shaft is HS Carbon/Epoxy. The APDL program forgenerating geometry, meshing it and imposing boundaryconditions has been represented in appendix C.

After solving under the given load and boundary conditionsfollowing results have been derived.

First vector sum of rotational deflection has been calculateddue to the above torque at different sections of the driveshaft.

Then Von-Misses stress has been calculated for differentsections of the tapered drive shaft.

Results of the above investigations have been presented inthe figures below


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Vector sum of rotational deflection of taperd shaft with taper

angle 1is 0.058858mm


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Von-Misses stress of the tapered shaft with taper angle

1.347.839 MPa


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Result.

It is clear from the above figure that deflection and Von-Misses

stress of the tapered drive shaft with taper angle 1 are of lesser

value. Rotational vector sum of the uniform drive shaft with sametorque load is 0.103686 mm but in case of the tapered drive shaft

with taper angle 1 is 0.058858 mm

Similarly Von-Misses stress of the uniform drive shaft is 350.927

N/mm2which is larger than the value of Von-Misses stress of

tapered shaft which is 347.839 N/mm2. After analyzing static analysis of the tapered shaft under torque

load of 3500 Nm, Modal analysis has been done on the taper shaft.

Figure below represents the result calculated from the modal

analysis.


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Modal analysis of 1 tapered drive shaft in 3 different mode of

vibration.

Deflection of shaft under 1stmode of vibration


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Deflection of shaft under 2ndmode of vibration and 3rdmode

of vibration


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Deflection of shaft under 3rdmode of vibration

It is clear from the above figures that the drive shaft will collapse

on 3rdmode of vibration.


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now taper angle has been increased to 1.5 and all the

results have been represented now Vector sum of rotational

deflection of taped shaft with taper angle 1.5.


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Von-Misses stress of the tapered shaft with taper angle

1.5.is 346.386 MPa


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Deflection of 1.5 taper shaft under 1stmode of vibration


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Deflection of 1.5 taper shaft under 2ndmode of vibration It

is clear from the above figures that the drive shaft wil l

collapse on 1st mode of vibration.


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Result and discussion

Parameters Uniform Shaft 1 Taper 1.5 Taper

Rotational

Deflection

0.103686 Degree 0.058858 Degree 0.048072 Degree

Von-Misses Stress 350.927 N/mm2 347.839 N/mm2 346.386 N/mm2

From the above study it is clear that tapered drive shaft exhibits lesser

deflection and less Von-Misses stress under a given torque. But with

increase of taper angle it shows some instability under vibration. So it is a

matter of further research to find out optimized taper angle so that

natural frequencies in different modes remains as low as possible.

CONCLUSIONS AND FUTURE SCOPE


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CONCLUSIONS AND FUTURE SCOPE From the research made in this work a conclusion may be drawn

that any other profile than the conventional uniform cylindricalprofile can also be used as transmission shaft. In this work instead

of an isotropic material like steel, a composite material used whichis orthotropic in character. Same torque has been imposed on anuniform drive shaft and on a tapered drive shaft made of Highstrength Carbon/Epoxy composite material. From the result it isclear that in tapered drive shaft less stress is created due to sametorque as applied on uniform drive shaft. But a problem is there astapered drive shaft is more vulnerable under vibration becausetapered drive shaft shows more natural frequency than uniformdrive shaft.

It has been clearly proved from this work that induced stress in thetapered drive shaft decreases with increase in taper angle of shaftbut natural frequency also increases with increase of taper anglewhich makes the concept unacceptable. Because, increase in naturalfrequency makes the design vulnerable under vibration.

So it is a matter of further research to find out optimal taper angleso that stress as well as natural frequency both can be reduced.

REFERENCES


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REFERENCES

[1] Fredrik Cato, Magnus Taskinen Noise and Vibration Investigation of Composite Shaft, A MasterDegree Thesis, Department of Mechanical Engineering, University of Kralskrona, Sweden, 1998;

[2]S.Rajendran and D.Q.Song, Finite Element Modelling of Delamination Buckling of CompositePanel Using ANSYS, Proceedings of 2nd Asian ANSYS User Conference, Nov 11-13, 1998,

Singapore.[3]Murat Ocalan, High flexibility rotorcraft drive shaft using flexible matrix composites and active

bearing control., Master Degree Thesis, Department of Mechanical Engineering, ThePennsylvania State University, 2002.

[4]Tomas Zackrisson, The Modeling and simulation of a driveline with an automatic gearbox, AMaster Degree Thesis, Department of Mechanical Engineering, Royal Institute of Technology,2003;

[5] T.Rangaswami, S.Vijayanarangan, R.A.Chandrashekhar, T.K.Venktesh and K.Anantharaman, optimal

design and analysis or automotive composite drive shaft. International Symposium of ResearchStudent on Material Science and Engineering, 2002-2004 chennai.

[6]David B. Adams, Optimization Frameworks for Discrete Composite Laminate StackingSequences, A Thesis for DOCTOR OF PHILOSOPHY, Virginia Polytechnic Institute and StateUniversity, 2005.

[7]Nicholas M. Northcote, The Modeling and Control of an Automotive Drivetrain, A Master Degree Thesis,Department of Mechanical Engineering, University of Sellenbosch, 2006;

[8]Yeow Ng, Al Kumnick, Determination of Cross-Ply Laminate Stacking Sequence for The Compression StrengthTesting of A unidirectional Boron EPOXY material., SAMPE Fall Technical conferences-Dallas, November 6-9,2006 Dallas, TX.

[9] Gummandi Sanjay & Akula Jagadeesh Kumar, Optimum Design and Analysis of a Composite Drive Shaft for anAutomobile, Master Degree Thesis, Department of Mechanical Engineering, Blekinge Institute of Technology,Karlskrona, Sweden, 2007.

[10]Duncan J. Lawrie, Development of a High Torque Density, Flexible, Composite Driveshaft, American HelicopterSociety 63rd Annual Forum, Virginia Beach, VA, May 1-3, 2007.

[11]M.A.K. Chowdhuri, R.A. Hossain, Design Analysis of an Automotive Composite Drive Shaft, InternationalJournal of Engineering and Technology Vol.2(2), 2010, 45-48


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.[12]Matthew james vick, Finite Element Study on the Optimization of an Orthotropic

Composite Toroidal Shell A Master Degree Thesis, School of Aerospace andMechanical Engineering, University of Oklahoma, 2010

[13]Prof. George Z. Voyiadjis & Prof. Peter I. Kattan, Mechanics of Composite Materials

with MATLAB, Springer Publication.[14]Robert M. Jones, Mechanics of Composite Materials, Taylor & Francis, 2ndEdition.

[15]The Focus, A Publication by Phoenix Analysis & Design Technologies (PADT) forANSYS Users.

[16]A Tutorial on Composite Analysis in ANSYS, ANSYS Inc.

Thank you sir

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A FEM BASED ANALYSIS AND MODIFICATION OF A COMPOSITE AUTOMOBILE DRIVE SHAFT