PATRAN Beginner’s Guide.pdf

PATRAN Beginner ’s Guide

Arul M Britto

November 25, 2003

Contents

1 Introduction

2 How to Start a PATRAN Session

2.1 Creating a New Database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2.2 Opening New Database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2.3 Leaving a PATRAN Session . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

2.4 Resuming a Previous Session . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3 Steps Involved in an analysis

3.1 Units . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4 Create Geometry

4.1 Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.1.1 Create Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.1.2 Create Curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.2 Checking and Correcting Mistakes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.2.1

Check the Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.2.2

Check the Curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.2.3 Deleting Points and Curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.3 Error and Warning Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.4 Entity Labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4.5 Checking the Surface Normal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5 Loads and Boundary Conditions

5.1 Dene the Load variation function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5.2 Loads and Boundary Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5.3 Load Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6 Dene Element Properties

6.1 Dene Material Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6.2 Element Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7 Finite Element Mesh

7.1 Create Mesh Seeds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7.2 Create the Mesh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7.3 Unpost the Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

7.4 Equivalence and Optimize . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8 Check Load/BCs

8.1 Loads/BCs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

8.2 Create a Load Case . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

CONTENTS

9 Perform the Analysis

9.1 Submit a ABAQUS Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

9.2 Accessing the ABAQUS Results from PATRAN . . . . . . . . . . . . . . . . . . . . . . . .

9.3 Post Processing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

9.4 Changing Display Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

9.5 Hard Copy of Plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

9.6 Stress Fringe Plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

9.7 Using Graph (XY) Plot to plot Stress variation . . . . . . . . . . . . . . . . . . . . . . . . .

9.8 To Quit from PATRAN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

10 Files

11 Troubleshooting

12 Frequently Asked Questions

2 HOW TO START A PATRAN SESSION

1 Introduction

PATRAN is a pre and post processing package for the nite element program ABAQUS. In addition

it has the capability of nite element analysis. This manual has been prepared for users who want to

use ABAQUS for nite element analysis. It also describes how once the ABAQUS analysis is run one

could carry out some post processing.

This manual tells the user how to run PATRAN in the Teaching system. It also has an example prob-

lem on how to set up the data for an ABAQUS analysis using PATRAN. It explains how a ABAQUS

job can be submitted from within PATRAN and after the successful completion of the job how to use

the post processing facilities.

2 How to Start a PATRAN Session

Find a suitable terminal for running PATRAN. These are the X-terminals in the main area of the DPO,

the PC-based X-terminals at the East end of the DPO, and the PC-based X-terminals in the EIET Lab

(Inglis building).

1. Log in using your user ID and password.

2. Run a window manager (example : twm& ). This is recommended. It is useful in the sense that

the PATRAN windows can be moved around and scaled. Do not run start, fvwm or fvwm2 .

3. Create a subdirectory and move to it.

Type mkdir patran (you need to do this only once.)

Type cd patran (you need to do this for each session.)

It is a good idea to re-start PATRAN in the directory in which the database resides. Even though

it is possible to start PATRAN in any directory and then change to the directory in which the

database is, it is not recommended. The reason is any new les created by PATRAN (example

session les) will be placed in the directory from which PATRAN was started.

If you do not know which is your current directory then type pwd . This will list the name of the

current working directory.

Some useful unix commands :

ls -l - will list all the les in the current directory.

cd - to return to your HOME directory.

rm le-name - to delete a le. Replace le-name with name of le to be deleted. Example

: rm bracket.dat

Here the subdirectory is called patran. All the PATRAN related les will be placed in this di-

rectory. When you start a session of PATRAN ensure that there is enough unused disk space

available within your quota to complete the current exercise. Contact the Computer Operators if

you require the quota to be increased.

Alternatively you can work in the /tmp directory. However les created in the /tmp directory

are deleted automatically after 48 hours. Therefore if you require these les please copy them to

your home directory within that time. First check whether there is enough free disk space. If the

free disk space is less than 10 Mbytes do not use the /tmp directory.

Type bdf /tmp

Check the amount available under the heading avail . This will be in KBytes.

Type cd /tmp

Type mkdir userid . Here substitute your user-id for userid .

Type cd userid to move to this directory.

If you start PATRAN from here then all the les created will be placed in this directory.

2 HOW TO START A PATRAN SESSION

Refresh graphics

Undo

Show

Hide

Labels

Front

View

Reset graphics

Labels

Heartbeat

Interrupt

Figure 1: Main Form

4. Type patran (Note : must be in lower case)

Warning

Warning : Do not use the start or fvwm window manager or any of its derivatives

(fvwm2). In the past some problems have been encountered while running PATRAN with

fvwm.

The MSC/PATRAN Main form ( Figure 1 , also see Appendix A, page 3) should appear

across the top of the screen.

At the top of the main form are

1. the pull-down menus, the on-line help, system icon buttons and the heartbeat.

Below that are

2. the application radio buttons

3. the toolbar icons

4. the history window area

5. the text command line

in that order (See Figure A1, in Appendix A).

The following message should appear in the history window :

MSC.PATRAN 2003 r2 has obtained 1 concurrent license(s) from FLEXlm ....

Then all is well. The MSC/PATRAN status indicator is displayed between the “interrupt” and

“undo” icons. This is the “ heartbeat”.

1. Green means ready and waiting.

2. Blue means busy, but can be interrupted.

3. Red means busy but not interruptible.

However if you get a message saying that PATRAN could not get a licence then try typing patran

again. If you still get the same message please contact the Computer Operators (operators@eng.cam.ac.uk)

and they should be able to sort out the problem.

If the licence was obtained successfully then wait for the heartbeat to turn Green. Only the ‘File’

command along the top row will appear in black. At this point that is the only command that can be

selected. The rest of the menus are greyed out.

In the rest of this document the actions to be taken by the user for completing the exercise is denoted

by the symbol .

Click on Help from the top menu and choose ‘Contents and Index...’.

This would list the following headers.

Before starting the exercise

2 HOW TO START A PATRAN SESSION

Figure 2: On-line Help Document

– Introduction to MSC.Patran

– Using MSC.Patran

– Interfaces

– Modules

– PCL

The selections to be made are indicated by numbered arrows in Figure 2 ,

Click on the “(Closed) Book” symbol or on the label “Using MSC.Patran”. This will open up and

display the subheadings. Then click on “MSC.Patran Workspace”.

Choose ‘Modelling Window’ from this menu (2 pages). This shows the Main form and the

Graphics viewport. Part of the Main form is shown in Figure 1 .

Choose ‘Menu Bar ’ and select ‘Menu Bar Keywords’. The items in the menu bar controls the

parameters of various system tasks. This page explains the keywords in the menu bar.

Below the Menu Bar is the Applications Bar. Below that is the Tool Bar. First we will consider the

Tool bar.

Click on ‘Tool Bar ’ and this should display the various palettes that make up the tool bar. The

most frequently used icons are included in the Tool bar.

Figure 2 shows the contents page as it appears at this stage.

Next click on the ’Applications Bar ’.

The essential work in using PATRAN is done by lling in the various forms in the ’Applications

Bar ’.

Click on ‘Entering and Retrieving Data’ in the contents page.

This will list (a) Forms, Widgets and Buttons (6 pages) (b) Selecting Entities (6 pages).

These sections explain how to ll in the various forms. For the present just browse through these

pages. At this stage it is not essential reading for completing the exercise given in this handout.

However these are for future reference to be read later for becoming procient with PATRAN.

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