35190600 Manual Student

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Introduction

ANSYS is a general purpose finite element modeling package for numerically

solving a wide variety of mechanical problems. These problems include:

static/dynamic structural analysis (both linear and non-linear), heat transfer

and fluid problems, as well as acoustic and electro-magnetic problems.

In general, a finite element solution may be broken into the following three

stages. This is a general guideline that can be used for setting up any finite

element analysis.

1. Preprocessing: defining the problem; the major steps in

preprocessing are given below:

o Define keypoints/lines/areas/volumes

o Define element type and material/geometric properties

o Mesh lines/areas/volumes as required

The amount of detail required will depend on the dimensionality of the

analysis (i.e. 1D, 2D, axi-symmetric, 3D).

2. Solution: assigning loads, constraints and solving; here we specify

the loads (point or pressure), constraints (translational and rotational)

and finally solve the resulting set of equations.

3. Post processing: further processing and viewing of the results; in

this stage one may wish to see:

o Lists of nodal displacements

o Element forces and moments

o Deflection plots

o Stress contour diagrams

ANSYS Environment

The ANSYS Environment for contains 2 windows: the Main Window and an

Output Window. Note that this is somewhat different from the previous version

of ANSYS which made use of 6 different windows.

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1. Main Window

Within the Main Window are 5 divisions:

a. Utility Menu

The Utility Menu contains functions that are available throughout

the ANSYS session, such as file controls, selections, graphic

controls and parameters.

b. Input Window

The Input Line shows program prompt messages and allows

you to type in commands directly.

c. Toolbar

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The Toolbar contains push buttons that execute commonly used

ANSYS commands. More push buttons can be added if desired.

d. Main Menu

The Main Menu contains the primary ANSYS functions,

organized by preprocessor, solution, general postprocessor,

design optimizer. It is from this menu that the vast majority of

modeling commands are issued. This is where you will note the

greatest change between previous versions of ANSYS and

version 7.0. However, while the versions appear different, the

menu structure has not changed.

e. Graphics Window

The Graphic Window is where graphics are shown and graphical

picking can be made. It is here where you will graphically view

the model in its various stages of construction and the ensuing

results from the analysis.

2. Output Window

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The Output Window shows text output from the program, such as

listing of data etc. It is usually positioned behind the main window and

can de put to the front if necessary.

ANSYS Files

Introduction

A large number of files are created when you run ANSYS. If you started

ANSYS without specifying a jobname, the name of all the files created will be

FILE.* where the * represents various extensions described below. If you

specified a jobname, say Frame, and then the created files will all have the file

prefix, Frame again with various extensions:

frame.db

Database file (binary). This file stores the geometry, boundary

conditions and any solutions.

frame.dbb

Backup of the database file (binary).

frame.err

Error file (text). Listing of all error and warning messages.

frame. out

Output of all ANSYS operations (text). This is what normally scrolls in

the output window during an ANSYS session.

frame.log

Logfile or listing of ANSYS commands (text). Listing of all equivalent

ANSYS command line commands used during the current session.

etc...

Depending on the operations carried out, other files may have been

written. These files may contain results, etc.

What to save?

When you want to clean up your directory, or move things from the /scratch

directory, what files do you need to save?

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If you will always be using the GUI, then you only require the .db file.

This file stores the geometry, boundary conditions and any solutions.

Once the ANSYS has started, and the jobname has been specified,

you need only activate the resume command to proceed from where

you last left off (see Saving and Restoring Jobs).

If you plan on using ANSYS command files, then you need only store

your command file and/or the log file. This file contains a complete

listing of the ANSYS commands used to get you model to its current

point. That file may be rerun as is, or edited and rerun as desired

(Command File Creation and Execution).

If you plan to use the command mode of operation, starting with an

existing log file, rename it first so that it does not get over-written or

added to, from another ANSYS run.

ANSYS: Saving and Restoring Jobs

Saving Your Job

It is good practice to save your model at various points during its creation.

Very often you will get to a point in the modeling where things have gone well

and you like to save it at the point. In that way, if you make some mistakes

later on, you will at least be able to come back to this point.

To save your model, select Utility Menu Bar -> File -> Save As Jobname.db.

Your model will be saved in a file called jobname.db, where jobname is

the name that you specified in the Launcher when you first started ANSYS.

It is a good idea to save your job at different times throughout the building and

analysis of the model to backup your work incase of a system crash or other

unforeseen problems.

Recalling orResuminga Previously Saved Job

Frequently you want to start up ANSYS and recall and continue a previous

job. There are two methods to do this:

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1. Using the Launcher...

o In the ANSYS Launcher, select Interactive... and specify the

previously defined jobname.

o Then when you get ANSYS started, select Utility Menu -> File

-> Resume Jobname.db .

o This will restore as much of your database (geometry, loads,

solution, etc) that you previously saved.

2. Or, start ANSYS and select Utility Menu -> File -> Resume from...

and select your job from the list that appears.

FEM Convergence Testing

Introduction

A fundamental premise of using the finite element procedure is that the body

is sub-divided up into small discrete regions known as finite elements. These

elements defined by nodes and interpolation functions. Governing equations

are written for each element and these elements are assembledinto a global

matrix. Loads and constraints are applied and the solution is then determined.

The Problem

The question that always arises is: How small do I need to make the elements

before I can trust the solution?

What to do about it...

In general there are no real firm answers on this. It will be necessary to

conduct convergence tests! By this we mean that you begin with a mesh

discretization and then observe and record the solution. Now repeat the

problem with a finer mesh (i.e. more elements) and then compare the results

with the previous test. If the results are nearly similar, then the first mesh is

probably good enough for that particular geometry, loading and constraints. If

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the results differ by a large amount however, it will be necessary to try a finer

mesh yet.

The Consequences

Finer meshes come with a cost however: more calculation time and large

memory requirements (both disk and RAM)! It is desired to find the minimum

number of elements that give you a converged solution.

Beam Models

For beam models, we actually only need to define a single element per line

unless we are applying a distributed load on a given frame member. When

point loads are used, specifying more that one element per line will not

change the solution, it will only slow the calculations down. For simple models

it is of no concern, but for a larger model, it is desired to minimize the number

of elements, and thus calculation time and still obtain the desired accuracy.

General Models

In general however, it is necessary to conduct convergence tests on your

finite element model to confirm that a fine enough element discretization has

been used. In a solid mechanics problem, this would be done by creating

several models with different mesh sizes and comparing the resulting

deflections and stresses, for example. In general, the stresses will converge

more slowly than the displacement, so it is not sufficient to examine the

displacement convergence.

Printing and Plotting ANSYS Results to a File

Printing Text Results to a File

ANSYS produces lists and tables of many types of results that are normally

displayed on the screen. However, it is often desired to save the results to a

file to be later analyzed or included in a report.

1. Stresses: instead of using 'Plot Results' to plot the stresses, choose'List Results'. Select 'Elem Table Data', and choose what you want to

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list from the menu. You can pick multiple items. When the list appears

on the screen in its own window, Select 'File'/'Save As...' and give a

file name to store the results.

2. Any other solutions can be done in the same way. For example select

'Nodal Solution' from the 'List Results' menu, to get displacements.

3. Preprocessing and Solution data can be listed and saved from the 'List'

menu in the 'Utility Menu bar'. Save the resulting list in the same way

described above.

Plotting of Figures

There are two major routes to get hardcopies from ANSYS. The first is a quicka raster-based screen dump, while the second is a scalable vector plot.

1.0 Quick Image Save

When you want to quickly save an image of the entire screen or the current

'Graphics window', select:

'Utility menu bar'/'PlotCtrls'/'Hard Copy ...'.

In the window that appears, you will normally want to select 'Graphics

window', 'Monochrome', 'Reverse Video', 'Landscape' and 'Save to:'.

Then enter the file name of your choice.

Press 'OK'

This raster image file may now be printed on a PostScript printer or included

in a document.

2.0 Better Quality Plots

The second method of saving a plot is much more flexible, but takes a lot

more work to set up as you'll see...

Redirection

Normally all ANSYS plots are directed to the plot window on the screen. To

save some plots to a file, to be later printed or included in a document or what

have you, you must first 'redirect' the plots to a file by issuing:'Utility menu bar'/'PlotCtrls'/'Redirect Plots'/'To File...'.

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Type in a filename (e.g.: frame.pic) in the 'Selection' Window.

Now issue whatever plot commands you want within ANSYS, remembering

that the plots will not be displayed to the screen, but rather they will be written

to the selected file. You can put as many plots as you want into the plot file.

When you are finished plotting what you want to the file, redirect plots back to

the screen using:

'Utility menu bar'/'PlotCtrls'/'Redirect Plots'/'To Screen'.

Display and Conversion

The plot file that has been saved is stored in a proprietary file format that must

be converted into a more common graphic file format like PostScript, or HPGL

for example. This is performed by running a separate program called display.

To do this, you have a couple of options:

1. select display from the ANSYS launcher menu (if you started ANSYS

that way)

2. shut down ANSYS or open up a new terminal window and then type

display at the Unix prompt.

Either way, a large graphics window will appear. Decrease the size of this

window, because it most likely covers the window in which you will enter the

display plotting commands. Load your plot file with the following command:

file,frame,pic

if your plot file is 'plots.pic'. Note that although the file is 'plots.pic' (with a

period), Display wants 'plots,pic'(with a comma). You can display your plots to

the graphics window by issuing the command like

plot,n

where n is plot number. If you plotted 5 images to this file in ANSYS, then n

could be any number from 1 to 5.

Now that the plots have been read in, they may be saved to printer files of

various formats:

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1. Colour PostScript: To save the images to a colour postscript file,

enter the following commands in display:

2. pscr,color,2

3. /show,pscr

4. plot,n

Where n is the plot number, as above. You can plot as many images

as you want to postscript files in this manner. For subsequent plots,

you only require the plot,n command as the other options have now

been set. Each image is plotted to a postscript file such as pscrxx.grph,

where xx is a number, starting at 00.

Note: when you import a postscript file into a word processor, the

postscript image will appear as blank box. The printer information is still

present, but it can only be viewed when it's printed out to a postscript

printer.

Printing it out: Now that you've got your color postscript file, what are

you going to do with it? Take a look here for instructions on colour

postscript printing at a couple of sites on campus where you can have

your beautiful stress plot plotted to paper, overheads or even posters!

5. Black & White PostScript: The above mentioned colour postscript

files can get very large in size and may not even print out on the

postscript printer in the lab because it takes so long to transfer the files

to the printer and process them. A way around this is to print them out

in a black and white postscript format instead of colour; besides thecolour specifications don't do any good for the black and white lab

printer anyways. To do this, you set the postscript color option to '3',

i.e. and then issue the other commands as before

6. pscr,color,3

7. /show,pscr

8. plot,n

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Note: when you import a postscript file into a word processor, the

postscript image will appear as blank box. The printer information is still

present, but it can only be viewed when it's printed out to a postscript

printer.

9. HPGL: The third commonly used printer format is HPGL, which stands

for Hewlett Packard Graphics Language. This is a compact vector

format that has the advantage that when you import a file of this type

into a word processor, you can actually see the image in the word

processor! To use the HPGL format, issue the following commands:

10. /show,hpgl

11. plot,n

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EX NO: 1 ANALYSIS OF SIMPLE TRUSS

AIM:

Determine the nodal deflections, reaction forces, and stress for the

truss system.

PROBLEM DESCRIPTION:

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Take Youngs Modulus E = 200GPa,

Area A = 3250mm2

Preprocessing: Defining the Problem

1. Give the Simplified Version a Title (such as 'Bridge Truss Tutorial').

In the Utility menu barselect File > Change Title:

The following window will appear:

1. Enter the title and click 'OK'. This title will appear in the bottom left

corner of the 'Graphics' Window once you begin. Note: to get the title to

appear immediately, select Utility Menu > Plot > Replot

2. Enter Keypoints

The overall geometry is defined in ANSYS using keypoints which

specify various principal coordinates to define the body. For this

example, these keypoints are the ends of each truss.

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o We are going to define 7 keypoints for the simplified structure as

given in the following table

keypointcoordinate

x y

1 0 0

2 1800 3118

3 3600 0

4 5400 3118

5 7200 0

6 9000 3118

7 10800 0(these keypoints are depicted by numbers in the above figure).

From the 'ANSYS Main Menu' select:

Preprocessor > Modeling > Create > Keypoints > In Active CS

o The following window will then appear:

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1.

o To define the first keypoint which has the coordinates x = 0 and

y = 0:

Enter keypoint number 1 in the appropriate box, and enter the

x,y coordinates: 0, 0 in their appropriate boxes (as shown

above).

Click 'Apply' to accept what you have typed.

o Enter the remaining keypoints using the same method.

Note: When entering the final data point, click on 'OK' to

indicate that you are finished entering keypoints. If you first

press 'Apply' and then 'OK' for the final keypoint, you will have

defined it twice!

If you did press 'Apply' for the final point, simply press 'Cancel'

to close this dialog box.

2. Units

Note the units of measure (ie mm) were not specified. It is the

responsibility of the user to ensure that a consistent set of units are

used for the problem; thus making any conversions where necessary.

3. Correcting Mistakes

When defining keypoints, lines, areas, volumes, elements, constraints

and loads you are bound to make mistakes. Fortunately these are

easily corrected so that you don't need to begin from scratch every time

an error is made! Every 'Create' menu for generating these various

entities also has a corresponding 'Delete' menu for fixing things up.4. Form Lines

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The keypoints must now be connected

We will use the mouse to select the keypoints to form the lines.

o In the main menu select: Preprocessor > Modeling > Create >

Lines > Lines > In Active Coord. The following window will

then appear:

o Use the mouse to pick keypoint #1 (i.e. click on it). It will now be

marked by a small yellow box.

o Now move the mouse toward keypoint #2. A line will now show

on the screen joining these two points. Left click and a

permanent line will appear.

o Connect the remaining keypoints using the same method.

o When you're done, click on 'OK' in the 'Lines in Active Coord'

window, minimize the 'Lines' menu and the 'Create' menu. Your

ANSYS Graphics window should look similar to the following

figure.

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1. Disappearing Lines

Please note that any lines you have created may 'disappear'

throughout your analysis. However, they have most likely NOT been

deleted. If this occurs at any time from the Utility Menu select:

Plot > Lines

2. Define the Type of Element

It is now necessary to create elements. This is called 'meshing'.

ANSYS first needs to know what kind of elements to use for our

problem:

o From the Preprocessor Menu, select: Element Type >

Add/Edit/Delete. The following window will then appear:

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Click on the 'Add...' button. The following window will appear.

1.

o For this example, we will use the 2D spar element as selected in

the above figure. Select the element shown and click 'OK'. You

should see 'Type 1 LINK1' in the 'Element Types' window.

o Click on 'Close' in the 'Element Types' dialog box.

2. Define Geometric Properties

We now need to specify geometric properties for our elements:

o In the Preprocessor menu, select Real Constants >

Add/Edit/Delete

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Click Add... and select 'Type 1 LINK1' (actually it is already selected). Click

on 'OK'. The following window will appear.

1.

o As shown in the window above, enter the cross-sectional area

(3250mm):

o Click on 'OK'.

o 'Set 1' now appears in the dialog box. Click on 'Close' in the

'Real Constants' window.

2. Element Material Properties

You then need to specify material properties:

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o In the 'Preprocessor' menu select Material Props > Material

Models

Double click on Structural > Linear > Elastic > Isotropic

1.

o We are going to give the properties of Steel. Enter the following

field:

1. EX = 2 e 5

o Set these properties and click on 'OK'. Note: You may obtain the

note 'PRXY will be set to 0.0'. This is poisson's ratio and is not

required for this element type. Click 'OK' on the window to

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continue. Close the "Define Material Model Behavior" by clicking

on the 'X' box in the upper right hand corner.

2. Mesh Size

The last step before meshing is to tell ANSYS what size the elements

should be. There are a variety of ways to do this but we will just deal

with one method for now.

o In the Preprocessor menu select Meshing > Size Cntrls >

ManualSize > Lines > All Lines

1.

o In the size 'NDIV' field, enter the desired number of divisions per

line. For this example we want only 1 division per line, therefore,

enter '1' and then click 'OK'. Note that we have not yet meshed

the geometry, we have simply defined the element sizes.

2. Mesh

Now the frame can be meshed.

o In the 'Preprocessor' menu select Meshing > Mesh > Lines and

click 'Pick All' in the 'Mesh Lines' Window

Your model should now appear as shown in the following window

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Plot Numbering

To show the line numbers, keypoint numbers, node numbers...

From the Utility Menu (top of screen) select PlotCtrls > Numbering...

Fill in the Window as shown below and click 'OK'

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Now you can turn numbering on or off at your discretion

Saving Your Work

Save the model at this time, so if you make some mistakes later on, you will at

least be able to come back to this point. To do this, on the Utility Menu select

File > Save as.... Select the name and location where you want to save your

file.

Solution Phase: Assigning Loads and Solving

You have now defined your model. It is now time to apply the load(s) and

constraint(s) and solve the the resulting system of equations.

Open up the 'Solution' menu (from the same 'ANSYS Main Menu').

1. Define Analysis Type

First you must tell ANSYS how you want it to solve this problem:

o

From the Solution Menu, select Analysis Type > NewAnalysis.

o Ensure that 'Static' is selected; i.e. you are going to do a static

analysis on the truss as opposed to a dynamic analysis, for

example.

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o Click 'OK'.

2. Apply Constraints

It is necessary to apply constraints to the model otherwise the model is

not tied down orgroundedand a singular solution will result. In

mechanical structures, these constraints will typically be fixed, pinned

and roller-type connections. As shown above, the left end of the truss

bridge is pinned while the right end has a roller connection.

o In the Solution menu, select Define Loads > Apply >

Structural > Displacement > On Keypoints

o Select the left end of the bridge (Keypoint 1) by clicking on it in

the Graphics Window and click on 'OK' in the 'Apply U,ROT on

KPs' window.

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o This location is fixed which means that all translational and

rotational degrees of freedom (DOFs) are constrained.

Therefore, select 'All DOF' by clicking on it and enter '0' in the

Value field and click 'OK'.

You will see some blue triangles in the graphics window

indicating the displacement contraints.

o

Using the same method, apply the roller connection to the rightend (UY constrained). Note that more than one DOF constraint

can be selected at a time in the "Apply U,ROT on KPs" window.

Therefore, you may need to 'deselect' the 'All DOF' option to

select just the 'UY' option.

3. Apply Loads

As shown in the diagram, there are four downward loads of 280kN,

210kN, 280kN, and 360kN at keypoints 1, 3, 5, and 7 respectively.

o Select Define Loads > Apply > Structural > Force/Moment >

on Keypoints.

o Select the first Keypoint (left end of the truss) and click 'OK' in

the 'Apply F/M on KPs' window.

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o Select FY in the 'Direction of force/mom'. This indicate that we

will be applying the load in the 'y' direction

o Enter a value of -280000 in the 'Force/moment value' box and

click 'OK'. Note that we are using units of N here, this is

consistent with the previous values input.

o The force will appear in the graphics window as a red arrow.

o Apply the remaining loads in the same manner.

The applied loads and constraints should now appear as shown below.

4. Solving the System

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We now tell ANSYS to find the solution:

o In the 'Solution' menu select Solve > Current LS. This indicates

that we desire the solution under the current Load Step (LS).

o The above windows will appear. Ensure that your solution

options are the same as shown above and click 'OK'.

o Once the solution is done the following window will pop up. Click

'Close' and close the /STATUS Command Window..

Postprocessing: Viewing the Results

Reaction Forces

A list of the resulting reaction forces can be obtained for this element

From the Main Menu select General Postproc > List Results >

Reaction Solu.

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Select 'All struc forc F' as shown above and click 'OK'

Deformation

o In the General Postproc menu, select Plot Results > Deformed

Shape. The following window will appear.

o Select 'Def + undef edge' and click 'OK' to view both the deformed

and the undeformed object.

o Observe the value of the maximum deflection in the upper left

hand corner

Deflection

o From the 'General Postproc' menu select Plot results > Contour

Plot > Nodal Solution. The following window will appear.

o Select 'DOF solution' and 'USUM' as shown in the above window.

Leave the other selections as the default values. Click 'OK'.

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o Looking at the scale, you may want to use more useful intervals.

From the Utility Menu select Plot Controls > Style > Contours

> Uniform Contours...

o Fill in the following window as shown and click 'OK'.

You should obtain the following.

o The deflection can also be obtained as a list as shown below.

General Postproc > List Results > Nodal Solution select 'DOF

Solution' and 'ALL DOFs' from the lists in the 'List Nodal Solution'

window and click 'OK'. This means that we want to see a listing of

all degrees of freedom from the solution.

Axial Stress

o From the General Postprocessormenu select Element Table >

Define Table

o Click on 'Add...'

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o As shown above, enter 'SAXL' in the 'Lab' box. This specifies the

name of the item you are defining. Next, in the 'Item,Comp' boxes,select 'By sequence number' and 'LS,'. Then enter 1 after LS, in

the selection box

o Click on 'OK' and close the 'Element Table Data' window.

o Plot the Stresses by selecting Element Table > Plot Elem Table

o The following window will appear. Ensure that 'SAXL' is selected

and click 'OK'

o Because you changed the contour intervals for the Displacement

plot to "User Specified" - you need to switch this back to "Auto

calculated" to obtain new values for VMIN/VMAX.

Utility Menu > PlotCtrls > Style > Contours > Uniform

Contours ...

o List the Stresses

From the 'Element Table' menu, select 'List Elem Table'

From the 'List Element Table Data' window which

appears ensure 'SAXL' is highlighted

Click 'OK'

Quitting ANSYS

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To quit ANSYS, select 'QUIT' from the ANSYS Toolbar or select Utility

Menu/File/Exit.... In the dialog box that appears, click on 'Save Everything'

(assuming that you want to) and then click on 'OK'.

RESULT:

Maximum Deflection :

Minimum Stress :

Maximum Stress :

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EX NO: 2 2D Plane Stress Bracket

AIM:

To analyse the given bracket for deflection and Stress by treating it as

plane stress condition.


This bracket is to be built from a 20 mm thick steel plate. A figure of the

plate is shown below.

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This plate will be fixed at the two small holes on the left and have a load

applied to the larger hole on the right.

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Defining the Basic Geometry

We are going to create this geometry using Boolean operations. These

procedures make it easy to combine simple geometric entities to create more

complex bodies. Begin by creating a planar rectangular area and then add

other areas to modify it. Start with,

ANSYS Main Menu -> Preprocessor -> (-Modeling-) Create -> (-Areas-)

Rectangle -> By 2 Corners.

Enter the parameters in the dialog box as shown below:

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This creates a 80 by 100 rectangle with its origin at (0,0). Now create circular

end on the right hand side.

Note that it is the responsibility of the user to ensure that a

consistent set of units are used for the various parameters in any

problem. It is best to first solve a simple problem for which analytical

results are available to check that all is correct.

Close the Rectangle menu and open up the Circle Menu.

Select Solid Circle and fill it in as follows...

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Don't worry for now that the areas overlap. They will be combined to

form a single area at a later time.

Also create a second and third circle for the left hand side, using the

following dimensions:

parameter circle 2 circle 3

WP X 0 0

WP Y 20 80

radius 20 20

One more thing to define... we need a rectangle on the left hand end to

fill between the two small circles.

Create a rectangle with

WP X -20

WP Y 20

width 20

height 60

Your screen should now look like the following...

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Boolean Operations

We now want to add these five discrete areas together to form one

area.

Back up to the Preprocessor menu and select Operate.

Then select (-Booleans-) Add -> Areas. A dialogue box then appears.

Now click on all five areas. Before pressing OK in the dialogue box,

check to see that the count parameter in the dialogue box is 5

(indicating 5 selected areas). If this not the case, try again.

Once OK is pressed, some processing takes place and finally one

large area is plotted.

The Bolt Holes

We now want to remove the bolt holes from this plate.

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Back up to Preprocessor and select (-Modeling-) Create -> (-Areas-)

Circle -> Solid Circle.

We will now create three circles with the parameters given below:

parameter circle 1 circle 2 circle 3

WP X 80 0 0

WP Y 50 20 80

radius 30 10 10

Again back up to the Preprocessor menu.

Now select (-Modeling-) Operate -> (-Booleans-) Subtract -> Areas.

Notice in the ANSYS Input window, that it is instructing you to pick or

enter base areas from which to subtract.

For our example, the base area is the first large plate that we created.

Select it.

Then click OK.

Next the ANSYS Input window will prompt for the areas to be

subtracted.

The areas to be subtracted are the three circles that we just created.

Click on the three circles that you just created and enter OK.

Some processing will take place and you will end up with the following:

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Elements and Meshing

Now that the area has been defined, it is time to select the element type, its

associated properties and finally, mesh the area.

Once again, back up to the Preprocessor menu.

At the top of the menu, select Element Type -> Add/Edit/Delete...

In the dialog box that appears, hit the Add... button.

A dialog box now appears that looks like the following:

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From this dialog box, you can select from a wide range of elements that are

listed in various groups. Use the scroll bars to take a look at the groupings.

For our problem, select solid (under the Structural heading) and the

quad 82 element, as shown in the above figure. This indicates that we

will be using an eight noded quadrilateral element. It has 4 corner

nodes and 4 midside nodes and possesses a quadratic shape function.

Then press OK.

Now select the Options... button.

Under the Element Behavior K3 label, select Plane strs w/thk. This

indicates that we desire a plane stress element with thickness.

Under the Extra Element Output K5 select nodal stress.

The dialog box should now look as follows.

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Click on OK when complete.

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The Meshing Process

The element properties are now defined. It is time to mesh the region.

Back up to the Preprocessor menu.

Select (-Meshing-) Shape & Size -> Global Elem Size....

In the Size field enter the number 5. This indicates that the element

edge length is to have a nominal size of 5 mm.

Press OK.

Back up to the Preprocessor menu.

Select (-Meshing-) Mesh -> Areas ....

Once the dialog box appears, click on the plate area and then OK.

You should then get a mesh that looks like:

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Loads and Constraints

Now that the geometry has been defined, it is time to apply the loads and

constraints to the body and finally solve the problem.

To start this next stage, we need to back up to the ANSYS Main Menu.

Select Solution -> (-Analysis Type-)New Analysis .... Make sure that

the type of analysis is set to Static.

Click on OK.

We will now apply the constraints.

Select (-Loads-) Apply -> (-Structural-) Displacement .

We will be fixing the two holes on the left side of the plate. The nodes

at these holes will be constrained in both the X and Y direction. To

facilitate the selection of the nodes, we will plot the nodes of the model.

To do this, go the the top ANSYS Utility menu and select Plot ->

Nodes.

We will now zoom on this graphic window. This is performed by going

to the PlotCtrls -> Pan, Zoom, Rotate ...

The following window appears:

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This window is rich with function. Try playing with some of the options. In

general, you select an operation in the window and then use your mouse to

activate it in the Graph Window.

For our purpose, select Box Zoom from this window.

Now click and drag over one of the small bolt holes on the left. Include

the hole and a few surrounding nodes.

Now go back to the Displacement menu and select On nodes....

We wish to select the first ring of nodes that define the bolt hole. This

selection may be performed in many ways including Single node

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selection or by multiple nodes using Box, Polygon or Circle. Try

whatever method you like. You can always Reset or Cancel the

operation.

In the end, you want to select the following nodes:

Press OK once the nodes are selected.

You will now be prompted to enter the value of the displacements on

these nodes. Fill out the dialog box as follows:

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Doing this indicates that all degrees of freedom at these nodes are

fixed to zero.

Do the same with the second small hole...

To see the whole plate again, you will need to go over to the Pan Zoom

Rotate window and select Back Up.

Zoom in on the other bolt hole and constraint it in the same way.

Load Application

Zoom back out to the full view of the plate.

We now will apply a single vertical load to the large bolt hole.

In the Apply menu, select the Force/Moment -> On Nodes.

Now pick the node at the bottom central region of the large bolt hole.

Press OK.

In the dialog box that appears, select a force value in the Y direction of

-1000. This is a downward acting force.

Your screen should now look like the following:

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Solution

Before proceeding, well will plot the elements again (Plot -> Elements

from the ANSYS Utility Menu).

From the Solution menu, select (-Solve-) Current LS. This indicates

that we want the current load step (or load condition) solved.

Click on the OK button on the dialog box that appears.

Close the /STAT window when the solution is complete.

Post-Processing: Viewing the Results

We are now ready to view the results. We will take a look at the both the

deflected shape and the stress contours.

Close the Solution menu, and enter the General PostProc menu.

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From this, select (-Read Results-) Last Set to indicate the last set of

the results are to be made current.

We will now take a look at a deformed plot of the object.

Select Plot Results -> Deformed Shape....

Now select the Def + undeformed and then press OK.

You should now have something on the screen that looks like:

Let's take a look at some stress contours for the plate.

In the Plot Results menu, select (-Contour Plot-) Nodal Solu....

Click the Stress field and then scroll down the right hand box to find

von Mises SEQV.

The dialog box should look like the following:

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Then press the Apply button.

Your graphic window should now look like:

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Any other desired stress field may also be plotted by selecting the

appropriate field in the right hand box and pressing Apply.

When you are done, press OK.

At this point, you might want to go ahead and change the geometry, loads

,constraints, material properties and resolve the problem.

Quitting ANSYS

To quit ANSYS, select QUIT from the ANSYS Toolbar or select Utility Menu ->

File -> Exit... In the dialog box that appears, click on Save Everything

(assuming that you want to) and then click on OK.

RESULT:Maximum Deflection :

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Minimum Stress :

Maximum Stress :

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EX NO: 3 CONDUCTION ANALYSIS OF A RECTANGULAR PLATE

AIM:

To analyze the given rectangular plate for temperature distribution.


Thermal conductivity of the plate, KXX=401 W/(m-K)

Preprocessing:

1. Change jobname. On the Utility Menu across the very top of the screen,

select:

File -> Change Jobname Enter platetmp, and click on OK.

2. Define element type: Preprocessor -> Element Type -> Add/Edit/Delete

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Click on Add. The Library of Element Types menu appears, as shown.

Scroll down to highlight Thermal Solid, and Quad 4node 55 as shown.

Click on OK, then Close.

.

3. Define Material Properties:

Preprocessor -> Material Properties -> Material Models

A dialogue box appears:

In the dialogue box that appears, on the right hand side, choose:

Thermal -> Conductivity -> Isotropic

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Another box appears. Enter 401 for KXX (thermal conductivity), then click on

OK.

KXX is the only material property needed for this analysis.

Close the other box (the one headed Define Material Model Behavior) by

clicking on the red X in the upper right-hand corner.

4. Create a rectangular area:

Preprocessor -> Modeling-> Create -> Areas -> Rectangle -> By Dimensions

Fill in the fields as shown, then click OK.

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5. Specify mesh density controls.

We will specify numbers of element divisions along lines.

Choose:

Preprocessor -> -Meshing- Size Cntrls -> Manual Size -> Lines->

Picked Lines

The picking menu (below left) appears. On the graphics window, click on the

bottom horizontal line (this is one of the 10 meter lines), to highlight it. Then,

click OK in the picking menu. Then, the Element Size menu (below right)

appears. Enter 6 for NDIV, as shown, then click OK

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Now, repeat the above process to specify 12 divisions along either of the

vertical lines. It is not necessary to specify a value for all four lines, you just

need a value for one of the horizontal lines and one of the vertical lines.

However, if you do specify a value for all four lines, make sure you use the

same number of divisions for both horizontal lines, and the same number of

divisions for both vertical lines. Of course, as specified above, the vertical and

horizontal lines do not need to have the same value. It is a problem, however,

if you specify different values for parallel lines on opposite ends of the plate.

6. Mesh the rectangle to create nodes and elements.

Preprocessor -> Meshing -> Mesh -> Areas -> Mapped -> 3 or 4 Sided

A picking menu appears. Select Pick All. The rectangle will be meshed. You

will see a number of small rectangles drawn on the larger rectangular area.

Each small rectangle is a finite element. There are four nodes associated

with each individual element. The nodes are at the corners of the elements.

Solution:

7. Apply temperatures around the edges:

Solution -> Define Loads-> Apply -> Thermal-> Temperature -> On

Lines

A picking menu appears. Highlight the two vertical lines (the 20 meter lines),

which have a temperature of 100 C, then click on OK in the picking menu.

The box on the next page appears. Highlight TEMP for DOFs to be

constrained, and enter 100 for VALUE, as shown.

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Click on TEMP for DOFs to be constrained and enter 150 for VALUE,

then click

OK.

Note: In some cases, when you want to repeat the same process two or more

times, you can click Apply in the box, instead of OK. That issues the

command, but leaves the box open. Clicking OK issues the command, but

leaves the box open. Sometimes, though, using the Apply option can cause

problems, if you are not careful. You might click on Apply to issue the

command, then immediately click on OK to close the box, and this issues

the command twice. Sometimes, that is not a problem, and sometimes it is.

So, in this exercise, you are just asked to click on OK in each case, and then

repeat the entire procedure. For the relatively simple modeling effort

undertaken in this exercise, this approach does not add much work, and is

probably less likely to result in errors.

8. Solve the problem:

Solution ->-Solve -> Current LS

Click OK in the Solve Current Load Step Box. Soon after clicking OK, you

should see a note in a box saying Solution is done! You may close this box.

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Postprocessing:

9. Plot the temperature distribution:

General Postproc -> Plot Results -> Contour Plot-> Nodal Solution

The box below appears. Click on DOF solution, then Temperature, then

click OK.

In the graphics window, a plot, as shown on the following page, should appear

Temperature Distribution Color Contour Plot: Note that the temperature

valuescorresponding to the colors are shown in the legend at the bottom of the plot.

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10. Select nodes along the plate center (x=5 meters).

For comparison with the analytical solution, you will need a listing of specific

temperatures at specific locations in the plate. ANSYS has calculated a

temperature at each node. Because of our method of creating the model by

automatic meshing of the rectangle, at this time, we do not know specific

node numbers at specific locations. But, we can get a listing of node numbers,

including the locations of each node, and also a listing of temperatures by

node numbers. To keep the amount of information to a workable level, it is

probably best to include in these lists only a subset of nodes. To get such a

list, we can first select only the nodes at x=5 meters. This is a case where it is

probably easiest to just use the direct command line entry option, rather than

operate through the menus. On the command line, type nsel,s,loc,x,5, as

shown below, and hit enter:

11. List the locations of the selected nodes.

On the top Utility Menu:

Choose List -> Nodes. In the box that appears, just click on OK at the

bottom. A

listing box appears:

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12. List the temperatures at each of these nodes.

General Postproc -> List Results -> Nodal Solution

In the box that appears, click on DOF Solution and Temperature, as

shown, then click OK.

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A listing, as shown on the following page, should appear. The locations of the

same nodes have already been listed, in Step 11 above, so the results for

these nodes can be checked with the analytical solution.

Re-select all nodes in the model for additional plotting, or listing, as desired.

To do this, simply type, at the command line: allsel, then hit enter:

Subsequent lists and plots will include all nodes. Steps 10, 11, and 12 couldbe repeated to get listings of temperatures of nodes at other locations.

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EX No: 4 TWO DIMENSIONAL TRUSS

AIM :

To analyze the given truss for deflection, stresses and reaction force.

Problem Description

Determine the nodal deflections, reaction forces, and stress for the truss

system shown below (E = 200GPa, A = 3250mm2

).

PROCEDURE:

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Preprocessor:

1. Define element type as LINK 1

2. Define geometric properties Cross sectional area : 3250e 6

m2

3. Define element material properties

E = 2 E 11 N/m2

PRXY = 0.3

4. Enter Key points

Key point X Y

1 0 02 1800 3118

3 3600 0

4 5400 3118

5 7200 0

6 9000 3118

7 10800 0

5. Form lines connect the keypoints

6. Meshing Size No.of divisions per line : 1

Processor:


2. Apply Constraints.

3. Apply Loads.

Solve the System.

Post Processor:

List the Following:

a. Deformation.

b. Reaction forces

c. Axial Stresses.

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AIM:

To find the various modes of frequencies for the given cantilever beam.


Preprocessing: Defining the Problem

The simple cantilever beam is used in all of the Dynamic Analysis Tutorials.

Solution: Assigning Loads and Solving


Solution > Analysis Type > New Analysis > Modal

ANTYPE,2

2. Set options for analysis type:

o Select: Solution > Analysis Type > Analysis Options..

The following window will appear

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o As shown, select the Subspace method and enter 5 in the 'No.

of modes to extract'

o Check the box beside 'Expand mode shapes' and enter 5 in the

'No. of modes to expand'

o Click 'OK'

Note that the default mode extraction method chosen is the

Reduced Method. This is the fastest method as it reduces the

system matrices to only consider the Master Degrees of

Freedom (see below). The Subspace Method extracts modes for

all DOF's. It is therefore more exact but, it also takes longer to

compute (especially when the complex geometries).

o The following window will then appear

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For this problem, we will use the default options so click on OK.


Solution > Define Loads > Apply > Structural > Displacement >

On Keypoints

Fix Keypoint 1 (ie all DOFs constrained).

4. Solve the System

Solution > Solve > Current LS

SOLVE

Postprocessing: Viewing the Results

1. Verify extracted modes against theoretical predictions

o Select: General Postproc > Results Summary...

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The following table compares the mode frequencies in Hz

predicted by theory and ANSYS.

Mode Theory ANSYS Percent Error

1 8.311 8.300 0.1

2 51.94 52.01 0.2

3 145.68 145.64 0.0

4 285.69 285.51 0.0

5 472.22 472.54 0.1

Note: To obtain accurate higher mode frequencies, this mesh

would have to be refined even more (i.e. instead of 10 elements,

we would have to model the cantilever using 15 or more

elements depending upon the highest mode frequency ofinterest).

2. View Mode Shapes

o Select: General Postproc > Read Results > First Set

This selects the results for the first mode shape

o

Select General Postproc > Plot Results > Deformed shape .Select 'Def + undef edge'

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The first mode shape will now appear in the graphics window.

o To view the next mode shape, select General Postproc > Read

Results > Next Set . As above choose General Postproc > Plot

Results > Deformed shape . Select 'Def + undef edge'.

o The first four mode shapes should look like the following:

3. Animate Mode Shapes

o Select Utility Menu (Menu at the top) > Plot Ctrls > Animate >

Mode Shape


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o Keep the default setting and click 'OK'

o The animated mode shapes are shown below.

Mode 1

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EX NO: 6 CONDUCTION ANALYSIS OF 2D COMPONENT

AIM:

The Simple Conduction Example is constrained as shown in the following

figure. Thermal conductivity (k) of the material is 10 W/m*C and the block is

assumed to be infinitely long.

Open preprocessor menu

ANSYS Main Menu > Preprocessor

Create geometry

Preprocessor > Modeling > Create > Areas > Rectangle > By 2

Corners > X=0, Y=0, Width=1, Height=1

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Define the Type of Element

Preprocessor > Element Type > Add/Edit/Delete... > click 'Add' >

Select Thermal Mass Solid, Quad 4Node 55

For this example, we will use PLANE55 (Thermal Solid, Quad 4node

55). This element has 4 nodes and a single DOF (temperature) at each

node. PLANE55 can only be used for 2 dimensional steady-state or

transient thermal analysis.

Element Material Properties

Preprocessor > Material Props > Material Models > Thermal >

Conductivity > Isotropic > KXX = 10 (Thermal conductivity)

Mesh Size

Preprocessor > Meshing > Size Cntrls > ManualSize > Areas >

All Areas > 0.05

Mesh

Preprocessor > Meshing > Mesh > Areas > Free > Pick All

ANALYSIS:

Define Analysis Type

Solution > Analysis Type > New Analysis > Steady-State

Apply Constraints

For thermal problems, constraints can be in the form of Temperature,

Heat Flow, Convection, Heat Flux, Heat Generation, or Radiation. In

this example, all 4 sides of the block have fixed temperatures.

Solution > Define Loads > Apply

Note that all of the -Structural- options cannot be selected. Thisis due to the type of element (PLANE55) selected.

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Thermal > Temperature > On Nodes

Click the Box option (shown below) and draw a box around the

nodes on the top line.

The following window will appear:

Fill the window in as shown to constrain the side to a constant

temperature of 500

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Using the same method, constrain the remaining 3 sides to a

constant value of 100

Orange triangles in the graphics window indicate the

temperature constraints.

Solve the System


RESULTS:

Results Using ANSYS

Plot Temperature

General Postproc > Plot Results > Contour Plot > Nodal Solu ...

> DOF solution, Temperature TEMP

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EX NO: 7 TWO DIMENSIONAL ANALYSIS OF FRAME

AIM:

To analyze the give frame model for Deflections, stress and Bending

Moment.

Problem Description:

The simplified version that will be used for this problem is that of a cantilever

beam shown in the following figure

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Procedure:

Preprocessor.

1. Define the element types Pipe 16

2. Define Geometric Element

Outer Diameter :25

Wall Thickness :2

3. Material Properties

Isotropic

E = 700000 MPa.

PRXY = 0.33

4. Define Key Points

KEYPOINTS X Y Z

1 0 325 0

2 0 400 0

3 500 400 0

4 500 0 05 825 0 50

6 825 0 -50

5. Create Lines.


Key points UX UY UZ

1 OK OK OK2 - - -

3 - - -

4 - - -

5 - OK OK

6 - OK OK

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Apply Loads;

Post Processor:

1. Plot Deflection, Stresses, Bending Moment Diagram.

RESULT:

Maximum Deflection:

Minimum Stress :

Key points UX UY UZ

1

2 - - -3 - - -

4 - 600 N -

5 - 200 N -

6 - - -

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Maximum Stress :

Bending Moment Diagram

EX NO: 8 HARMONIC ANALYSIS OF CANTILEVER BEAM

AIM:

The purpose of this exercise is to explain the steps required to performHarmonic analysis the cantilever beam shown below.


We will now conduct a harmonic forced response test by applying a cyclic

load (harmonic) at the end of the beam. The frequency of the load will be

varied from 1 - 100 Hz. The figure below depicts the beam with the application

of the load.

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1. Define Analysis Type (Harmonic)

Solution > Analysis Type > New Analysis > Harmonic

ANTYPE,3

2. Set options for analysis type:

o Select: Solution > Analysis Type > Analysis Options..


o As shown, select the Full Solution method, the Real +

imaginary DOF printout format and do not use lumped mass

approx.

o Click 'OK'

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The following window will appear. Use the default settings

(shown below).


o Select Solution > Define Loads > Apply > Structural > Displacement >

On Nodes

o Constrain all DOF

4. Apply Loads:

o Select Solution > Define Loads > Apply > Structural >

Force/Moment > On Nodes

o Select the node at x=1 (far right)

o The following window will appear. Fill it in as shown to apply a

load with a real value of 100 and an imaginary value of 0 in the

positive 'y' direction

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5. Set the frequency range

o Select Solution > Load Step Opts > Time/Frequency > Freq

and Substps...

o As shown in the window below, specify a frequency range of 0 -

100Hz, 100 substeps and stepped b.c..

By doing this we will be subjecting the beam to loads at 1 Hz, 2

Hz, 3 Hz, ..... 100 Hz. We will specify a stepped boundary

condition (KBC) as this will ensure that the same amplitude (100

N) will be applyed for each of the frequencies. The ramped

option, on the other hand, would ramp up the amplitude where

at 1 Hz the amplitude would be 1 N and at 100 Hz the amplitude

would be 100 N.

You should now have the following in the ANSYS Graphics

window

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6. Solve the System


SOLVE

We want to observe the response at x=1 (where the load was applyed) as

a function of frequency. We cannot do this with General PostProcessing

(POST1), rather we must use TimeHist PostProcessing (POST26). POST26

is used to observe certain variables as a function of either time or frequency.

1. Open the TimeHist Processing (POST26) Menu

Select TimeHist Postpro from the ANSYS Main Menu.

2. Define Variables

In here we have to define variables that we want to see plotted. By

default, Variable 1 is assigned eitherTime orFrequency. In our case

it is assigned Frequency. We want to see the displacement UY at the

node at x=1, which is node #2. (To get a list of nodes and their

attributes, select Utility Menu > List > nodes).

o Select TimeHist Postpro > Variable Viewer... and the following

window should pop up.

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o Select Add (the green '+' sign in the upper left corner) from this

window and the following window should appear

o We are interested in the Nodal Solution > DOF Solution > Y-

Component of displacement. Click OK.

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o Graphically select node 2 when prompted and click OK. The

'Time History Variables' window should now look as follows

3. List Stored Variables

o

In the 'Time History Variables' window click the 'List' button, 3buttons to the left of 'Add'

The following window will appear listing the data:

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4. Plot UY vs. frequency

o In the 'Time History Variables' window click the 'Plot' button, 2

buttons to the left of 'Add'

The following graph should be plotted in the main ANSYS

window.

Note that we get peaks at frequencies of approximately 8.3 and

51 Hz. This corresponds with the predicted frequencies of 8.311

and 51.94Hz.

To get a better view of the response, view the log scale ofUY.

o Select Utility Menu > PlotCtrls > Style > Graphs > Modify

Axis


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o As marked by an 'A' in the above window, change the Y-axis

scale to 'Logarithmic'

o Select Utility Menu > Plot > Replot

o You should now see the following

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This is the response at node 2 for the cyclic load applied at this

node from 0 - 100 Hz.

o For ANSYS version lower than 7.0, the 'Variable Viewer' window

is not available. Use the 'Define Variables' and 'Store Data'

functions under TimeHist Postpro. See the help file for

instructions.

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EX NO: 9 Thermal Analysis of Stepped Bar.

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EX NO: 10 ANALYSIS OF BEAM WITH DISTRIBUTED LOAD

AIM:

The purpose of this exercise is to explain how to apply distributed loads and

use element tables to extract data.

Problem Definition:

A distributed load of 1000 N/m (1 N/mm) will be applied to a solid steel beam

with a rectangular cross section as shown in the figure below. The cross-

section of the beam is 10mm x 10mm while the modulus of elasticity of the

steel is 200GPa.

1. Open preprocessor menu

2. Give example a Title

Utility Menu > File > Change Title ...

/title, Distributed Loading

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3. Create Keypoints

Preprocessor > Modeling > Create > Keypoints > In Active CS

We are going to define 2 keypoints (the beam vertices) for this

structure as given in the following table:

Keypoint Coordinates (x,y)

1 (0,0)

2 (1000,0)

4. Define Lines

Preprocessor > Modeling > Create > Lines > Lines > Straight

Line

L,K#,K#

Create a line between Keypoint 1 and Keypoint 2.

5. Define Element Types

Preprocessor > Element Type > Add/Edit/Delete...

For this problem we will use the BEAM3 element. This element

has 3 degrees of freedom (translation along the X and Y axis's,

and rotation about the Z axis). With only 3 degrees of freedom,

the BEAM3 element can only be used in 2D analysis.

6. Define Real Constants

Preprocessor > Real Constants... > Add...

In the 'Real Constants for BEAM3' window, enter the following

geometric properties:

i. Cross-sectional area AREA: 100

ii. Area Moment of Inertia IZZ: 833.333

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iii. Total beam height HEIGHT: 10

This defines an element with a solid rectangular cross section

10mm x 10mm.

7. Define Element Material Properties

Preprocessor > Material Props > Material Models > Structural >

Linear > Elastic > Isotropic

In the window that appears, enter the following geometric

properties for steel:

i. Young's modulus EX: 200000

ii. Poisson's Ratio PRXY: 0.3

iii.

8. Define Mesh Size

Preprocessor > Meshing > Size Cntrls > ManualSize > Lines >

All Lines...

For this example we will use an element length of 100mm.

9. Mesh the frame

Preprocessor > Meshing > Mesh > Lines > click 'Pick All'

10. Plot Elements

Utility Menu > Plot > Elements

You may also wish to turn on element numbering and turn off keypoint

numbering

Utility Menu > PlotCtrls > Numbering ...

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Solution > Analysis Type > New Analysis > Static

ANTYPE,0


Solution > Define Loads > Apply > Structural > Displacement >On Keypoints

Pin Keypoint 1 (ie UX and UY constrained) and fix Keypoint 2 in

the y direction (UY constrained).

3. Apply Loads

We will apply a distributed load, of 1000 N/m or 1 N/mm, over the

entire length of the beam.

o Select Solution > Define Loads > Apply > Structural >

Pressure > On Beams

o Click 'Pick All' in the 'Apply F/M' window.

o As shown in the following figure, enter a value of 1 in the field

'VALI Pressure value at node I' then click 'OK'.

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The applied loads and constraints should now appear as shown in the

figure below.

Note:

To have the constraints and loads appear each time you select

'Replot' you must change some settings. Select Utility Menu >

PlotCtrls > Symbols.... In the window that appears, select

'Pressures' in the pull down menu of the 'Surface Load Symbols'

section.

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4. Solve the System


SOLVE

Plot Deformed Shape

General Postproc > Plot Results > Deformed Shape

PLDISP.2

1. Plot Principle stress distribution

As shown previously, we need to use element tables to obtain principle

stresses for line elements.

1. Select General Postproc > Element Table > Define Table

2. Click 'Add...'

3. In the window that appears

a. enter 'SMAXI' in the 'User Label for Item' section

b. In the first window in the 'Results Data Item' section scroll

down and select 'By sequence num'

c. In the second window of the same section, select

'NMISC, '

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d. In the third window enter '1' anywhere after the comma

4. click 'Apply'

5. Repeat steps 2 to 4 but change 'SMAXI' to 'SMAXJ' in step 3a

and change '1' to '3' in step 3d.

6. Click 'OK'. The 'Element Table Data' window should now have

two variables in it.

7. Click 'Close' in the 'Element Table Data' window.

8. Select: General Postproc > Plot Results > Line Elem Res...

9. Select 'SMAXI' from the 'LabI' pull down menu and 'SMAXJ'

from the 'LabJ' pull down menu

RESULT:

Element Stress results are:

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EX NO: 11 Thermal Analysis of a long Bar.

Introduction:

In this example you will learn to model a 2D block subjected to varying

boundary conditions. Using ANSYS will allow you to output the temperature

distribution in an extremely simple and accurate way. By using any

combination of these boundary conditions one can model almost any 2D heat

transfer situation.

AIM:

To determine the nodal temperature distribution and create contour

plot.

Problem Description:

We assume that our block is a rectangle made entirely of steel.

All units are S.I.

Boundary Conditions:

1) The top is insulated.

2) The right side has a constant temperature of 100K.

3) The left side has constant heat flux into the block of 50 W/m^2.

4) The bottom side is exposed to a convective boundary layer.

5) Heat is uniformly generated in the bock at a rate of 20 W/m^2.

Material Properties: (Steel)

h = 50 W/(m^2*K)

k = 20 W/m K

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Basic Outline of the Problem:

Preprocessing:

1. Start ANSYS.

2. Create areas.

3. Define the material properties.

4. Define element type. (Quad 8node 77 element, which is a 2-D element for

heat transfer analysis.)

5. Specify meshing controls / Mesh the areas to create nodes and elements.

Solution:

6. Specify boundary conditions.

7. Solve.

Postprocessing:

8. Plot the temperature distribution.

Exit:

9. Exit the ANSYS program, saving all data.

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Material Properties:

Now that we have built the model, material properties need to be

defined such that ANSYS understands how heat travels through this

steel solid.

Go to the ANSYS Main Menu

Click Preprocessor>Material Props>Material Models.

Thermal>Conductivity>Isotropic. (Double click Isotropic).

Fill in 20 for Thermal conductivity. Click OK.

Now exit the Define Material Model Behavior Window

Element Properties:

Click Preprocessor>Element Type>Add/Edit/Delete... In the 'Element

Types' windowthat opens click on Add:

Type 1 in the Element Typereference number.

Click on Thermal Mass Solid and select Quad 8node 77. Click OK.

Close the 'Elementtypes' window.

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Now we have selected Element Type 1 to be a Thermal Solid 8node

Element. This finishes the section defining how the part is to be

analyzed.

Meshing:

This section is responsible for telling ANSYS how to divide the block

such that it has enough nodes, or points, to analyze to make an

accurate enough analysis.

Go to Preprocessor>Meshing>Size Controls>Manual

Size>Lines>All Lines. In the menu that comes up type 0.1 in the field

for Element edge length.

Click on OK. Now when you mesh the figure ANSYS will automatically

create square meshes that have an edge length of0. 1m along the

lines you selected.

Now go to Preprocessor>Meshing>Mesh Attributes>Default

Attributes. The window is shown below:

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This window appears such that the program knows you are sure

that you have selected the right material to mesh (selected by the

Element Type Number), and the right Material Number (1, as

defined in the Material Properties section). Once this has beenverified, Click OK and proceed to

Preprocessor>Meshing>Mesh>Areas>Free

A popup window will appear on the left hand side of the screen.

This window allows you to select the area to be meshed.

Click anywhere within the blue rectangle you created to select the

area and then click OK in the pop-up window.

Boundary Conditions and Constraints:

Now that we have modeled the block and defined how ANSYS is to

analyze the block we will apply the appropriate Boundary

Conditions.

Go to Preprocessor>Loads>Define Loads>Apply>Thermal (from

here one can apply any of the loads, or Boundary Conditions,

offered by ANSYS.)

Apply Convection (Base)

First well apply the Convection Boundary layer at the base of the plate.

For this click Convection>On Lines within the Thermal Load category.

A popup window will appear on the left hand side of the screen. This

window allows you to select the line you wish the load to be applied.

Select the base of the plate and click OK. The following window will

appear:

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Fill in the h value in the Film Coefficient blank and the Air

temperature in the Bulk Temperature blank. Click OK when

finished.

Apply Constant Temperature (Right side)

Now well apply the given temperature boundary condition on the

right side of the block.

This time, within the Thermal Load category select

Temperature>On Lines.

A popup window will appear on the left hand side of the screen.

This window allows you to select the line you wish the load to be

applied.

Click the right side of the block and then OK.

Enter100 in the popup window as the set temperature for the right

side:

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Apply Heat Flux (Left Side)

Now to apply the Heat Flux into the left side of the plate...

Within the Thermal Load category again, select Heat Flux>On Lines

and click OK. Then enter50 into the blank and Click OK.

Insulated Surface (Top)

Since the top of the block is insulated we dont need to define a specificboundary condition for the top, so we add uniform heat generation to the block

as a whole and

were done.

Apply Heat Generation

The next step is to add the constraint of heat generation.

Preprocessor>Loads>Define Loads>Apply>Thermal>Heat

Generat>On Areas. (Heat Generated is just short for Heat

Generation). You select Areas this time because you have to apply

this condition uniformly across the block.

Click anywhere within the area to select it and then click OK.

Enter20 as the heat generation value in the pop-up window that

appears:

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Now we have applied all the necessary boundary conditions so we

move on to the Solution.

Solution:

Go to ANSYS Main Menu>Solution>Analysis Type>New Analysis.

Select Steady State and click on OK.

Go to Solution>Solve>Current LS.

An error window may appear. Click OK on that window and ignore it.

Wait for ANSYS to solve the problem.

Click on OK and close the 'Information' window.

Post-Processing:

This section is designed so that one can list the results of their analysis

as a nodal solution

Go to the ANSYS Main Menu. Click

General Postprocessing>List Results>Nodal Solution.

Select DOF solution and Temperature. Click on OK.

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Modification / Plotting the Results:

First go to General Postprocessing>Plot Results>Contour Plot>Nodal

Solution. The following window will come up:

Select DOF solution and Temperature to be plotted and click OK.

The output will be like this:

RESULT:

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EX NO: 12 ANALYSIS OF CORNER BRACKET

AIM:

A simple static analysis of the corner bracket to control, if the bracket will yield

under loading.

PROBLEM DECRIPTION:

The dimensions of the corner bracket are given below. The bracket is made of

steel with a Young's modulus of E=205 GPa (GPa = 109 N/m2) and the

Poisson's ratio of 0.27 and a yield stress, including a safety factor, of 400

MPa.

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We will assume plane state of stress, (plane stress is a state of stress in

which the normal and shear stress perpendicular to the plane is assumed to

be zero).

Preferences:

Select Structural

Preprocessing

Define element types and options

Main menu: Preprocessor- Element Type - Add/Edit/Delete..

Add.. an element type

Select Structural Solid family Quad 8 node 82 element and press OK

In the element type dialog now select options to specify

Plane stress w/thk (with thickness)

OK to close the Element type options dialog

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Close the Element type dialog

Defining real constants

Main menu: Preprocessor- Real Constant

Add a real set

OKfor PLANE82

Enter0.01 for THK ( 10 mm thickness)

Press Close to finish the definition of the real constant dialog

Define material properties

Main menu: Preprocessor- Material Props - Constant - Isotropic

OKto define material set 1

Enter205.e9 for EX (Young's modulus)

Enter0.27 for NUXY (Poisson's ratio)

Press OK to define and close material set 1

Define rectangles

Main menu: Preprocessor - Modeling - Create - Areas - Rectangle - By

dimensions

Enter0, 0.15, -0.025, 0.025 for X1,X2,Y1 and Y2 (Tab key between

entries)

Apply to define the first rectangle

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Enter0.1, 0.15, -0.025, -0.075 for X1,X2,Y1 and Y2 for the second

rectangle

OK to define the second rectangle and close the dialog

Change plot controls and replot

To clearly distinguish between the areas just created we will turn on the area

numbers and color control is turned on. This is done from the utility menu:

Utility menu: PlotCtrls - Numbering

Turn on area numbering and press OK to close and replot

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Change working plane to polar and create first circle

Utility menu: PlotCtrls - Pan, Zoom, Rotate

Click on the small dot (.) to zoom out

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Let the Pan, Zoom, Rotate dialog be open you'll need it later

Utility menu: Workplane - Display Working Plane (toggle on)

The WP origin will now be visible on top of the global origin. Next, change the

WP to polar, snap on, snap increment and display grid spacing to 0.005, the

polar radius to 0.025 and the tolerance to 0.001.

Utility menu: Workplane - WP settings

Set the parameters according to the display and click OK whenfinished

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The next step is to create the first circle using the picking function in ANSYS.

You can at this point use the Pan,Zoom,Rotate dialog to zoom in the polar

WP coordinate system. Use the big dot to zoom in and the to pan.

Main menu: Preprocessor - Modeling - Create - Areas - Circle - Solid Circle

Pick center point (left mouse button) at WP polar system (0,0). (Note

the message in the Input window)

Move the mouse to 0.025 radius and click left mouse button

OK to close picking menu

Move working plane and create second circle

First we will move the WP origin to the center of the other circle. Then we will

create the other circle in the same manner as the first one. The simplest way

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to move the WP without entering the number offset is to pick the average of

two keypoints at the lower end of the other rectangle.

Utility menu: Workplane - Offset WP to - Keypoints

Pick keypoint 1 at lower left corner of rectangle

Pick keypoint 2 at lower right corner of rectangle

OK to finish picking offset WP


Pick center point (left mouse button) at WP polar system (0,0).



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Toolbar: SAVE_DB

Add areas

We need to add the different areas together to get one continuous area. This

is done with the boolean operation: Addareas

Main menu: Preprocessor - Modeling - Operate - Boolean - Add - Areas

Click on Pick All in the Add areas dialog

OK to add all areas together

Toolbar: SAVE_DB

Create line fillet

We need to fill in the radius between the intersection of the two rectangles.

But first we turn off the line numbers and turn off the display of the working

plane.

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Utility menu: PlotCtrls - Numbering

Turn on line numbering and press OK to close and replot

Utility menu: Workplane - Display Working Plane (toggle off)

Your graphic display should now look something like:

Main menu: Preprocessor - Modeling - Create - Lines - Line Fillet

Pick line 17 and 8

Enter 0.01 (10 mm) as fillet radius

OK to create fillet and close dialog box

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Create fillet area

The next step is to create a fillet area that can be added to the rest of the

bracket. Before you continue to create a fillet area of the lines you just creates

use the Pan, Zoom, Rotate dialog under Utility menu: PlotCtrls to zoom in

the fillet radius as shown above.

Main menu: Preprocessor - Modeling - Create - Areas - Arbitrary - By Lines

Pick lines L4, L5, L1

OK to create area and close dialog

Use the Pan, Zoom, Rotate dialog again and click on Fit and plot the areas

under

Utility Menu: Plot - Areas

Your plot should now look like:

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Add areas together

Now add the fillet area to the bracket area. Use the same procedure as in

step 10.

Main menu: Preprocessor - Modeling - Operate - Boolean - Add - Areas

Click on Pick All in the Add areas dialog

OK to add all areas together

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Create first bolt hole

The holes have a radius of 12.5 mm so we need to change the WP snap and

display increment to 2.5mm if we want to pick the circle origin and radius

when we create the holes.

Utility menu: Workplane - Display Working Plane (toggle on)

Utility menu: Workplane - WP settings

Change the snap incr and display spacing to 0.0025 and click OK

when finished

Now create the first hole:


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Move working plane and create the second bolt hole

First we move WP back to the global origin:

Utility menu: Workplane - Offset WP to - Global origin

Then we create the other hole





To view the result so far we plot all lines (plotting areas can result in that

some areas hidden by others):

Utility menu: Plot - Lines

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Toolbar: SAVE_DB

Subtract the bolt holes from the bracket

To finalize the model we only have to subtract the bolt areas from the bracket

to create holes.

Main menu: Preprocessor - Modeling - Operate - Booleans - Subtract -

Areas

Pick bracket as base area from which to subtract

Apply (in picking dialog, Not OK!)

Pick both bolt holes as areas to be subtracted

OK to subtract and close the picking menu

Final model of the corner bracket

Toolbar: SAVE_DB

Mesh the area

We will specify a global element size to control overall mesh density:

Main Menu: Preprocessor- Meshing- Shape & Size - Global Elem Size

Type 0.01 in the SIZE Element edge length OK to close dialog

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Finish the preprocessing by meshing the bracket

Main Menu: Preprocessor - Meshing - Mesh - Areas

Pick the bracket area

OK to mesh and close the picking menu

Solution

Apply displacement constraints

The upper bolt hole is constrained, e.g. we have to lock the displacements

(set them to zero) of the nodes on the circumference. Since we have not

explicitely defined where the nodes on the circumference are located,

(ANSYS automatically did that), we'll lock the 4 keypoints on the

circumference and tell ANSYS the all nodes located along the lines between

the keypoints will also be locked.

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Main Menu: Solution - Loads - Apply - Structural - Displacement - On

Keypoints

Pick the four keypoints around the upper left-hand hole

OK to complete in the picking menu

Click on All DOF (Degree Of Freedom)

Click to yes to expand displacement constraints to nodes

OK to set constraint and close dialog

Toolbar: SAVE_DB

Apply pressure load

We'll now apply the tapered (linearly varying) pressure to the bottom right bolt

hole. In ANSYS a hole is made of four lines defining the

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35190600 Manual Student