Stellenbosch Undergraduate FEA Assignment Assistance.

Published 2015-08-17
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On this page, example assignments from 2014 of the Stellenbosch University's Mechanical Engineering department will be set up using Patran and solved using MSC Nastran.

For complicated geometry cleanup and preparation, MSC Apex may be used. The assignments were prepared by Dr Martin Venter from the Stellenbosch University's Mechanical Engineering department. The videos on this page will focus on the use of the respective software packages and not on answering all the assignment questions. Student should be able to follow the videos and then use the software to set up and solve similar problems and use the tools provided to answer the relevant questions. The videos on this page was created by Paul Naudé from ESTEQ with the sole purpose to aid students in using the relevant software products from MSC Software when completing the assignments. Please use your own discretion and engineering judgement when following the steps provided.

On this page:

    1. Resources
    2. Getting started using Patran and MSC Nastran
    3. Patran and Nastran MUST KNOW Tips and Tricks
    4. Assignments
    5. Trouble shooting analysis failure

1.Resources

I.Download and Install MSC Nastran (it includes Patran) which will be used for all the assignments from MSC Software

    • Accept most of the default options during the installation and
    • When asked for the various CAD license files, leave it blank to skip unless you happen to have any of the referenced CAD packages licensed on your computer (this is not required, only for directly importing from those CAD formats)
    • NB:When picking a start-in folder, make sure NONE of the folder names contain any spaces! E.g. DO NOT choose any folder such as "C:\My Documents" due to the space in the folder name. Nastran WILL NOT run if your model is saved there. Underscores and the minus signs are accepted though, such as "C:\My_FEA-Projects"
    • After installing MSC Nastran, these two shorcuts should be available on your desktop: NastranPatranSE Icons
    • MSC Nastran (the solver) will be used to analyse the problems and Patran (the user interface) will be used to build the models and view the results from Nastran

II.For a view of the future, or if you do not have access to a CAD package, or need to prepare complicated geometry for analysis, such as mid-surfacing and CAD clean-up, also download and Install MSC Apex.

    • To get started using MSC Apex, follow the tips and tricks here
    • MSC Apex is a next generation CAE tool with currently very strong CAD clean-up capabilities and some basic FEA setup and solving capabilitiesMSC Apex Icon
    • Geometry creation is 4 times quicker (and easier) in MSC Apex than in Patran (see Assignment 2 Question 2).

III.To help you better understand the FEA process flow and where in the Patran user-interface to find the associated tools, I recommend downloading this file:

Patran FEA Process_s

2. Video: Getting started using Patran and MSC Nastran

Questions you must be able to answer now after watching the above video:

    1. What common keyboard character are NOT allowed in any file name when using Nastran?
    2. How do you nicely fit the model window inside the Patran interface?
    3. What is the importance of the value you have to type in when starting a new model?
    4. What is common to both the Patran tab order and the FEA Process shown in the previous flow chart?
    5. How do you manipulate what functions you have available on the right side of the model in the Patran user interface?
    6. What effect does the order in which you choose items in the 3 drop down menus on the right side have?
    7. Which button always need to be clicked for any data entered to become active or used in a Patran model?
    8. What does the three dots (...) after the text on some buttons signify?
    9. What does clicking on an icon in the top menu do to the right side form dropdown boxes?
    10. Not all the Patran functions are represented by icons. How do you get access to the rest?
    11. Where do you change the setting whether only fully enclosed entities or also partially enclosed entities are selected when selecting by draging a rectangle over multiple entities?
    12. Where is the model name as well as the active group name displayed in Patran?

3. Patran and Nastran MUST KNOW Tips and Tricks

I. The Patran & Nastran files created and exchanged

II. NO Spaces allowed

III. Geometry Importing Units and Units in general

IV. Global Model Tolerance

V. ONE Undo, BUT Unlimited undos if you know how

VI. Unimportant but useful: Using a model template

4. Assignments

    1. Assignment 1: Cantilevered beam
    2. Assignment 2: Question 1: Tapered plate under stress
    3. Assignment 2: Question 2: S-plate under stress
    4. Assignment 3: Question 1: Rotating rings

1. Assignment 1 overview:
Assignment_1

I. Video: Steps to create and setup the FEA model in Patran

II. Video: Steps to create and setup the FEA model in MSC Apex

2. Assignment 2, Question 1 Overview:

A1Q1

sketch

I. Video: Steps to create and setup the FEA model in Patran

II. Video: Steps to create and setup the FEA model in MSC Apex

3. Assignment 2, Question 2 Overview:

I. Video: Steps to create and setup the FEA model in Patran

II. Video: Steps to create and setup the FEA model in MSC Apex (and save 10 minutes creating the Geometry)

4. Assignment 3, Question 1 Overview:
SUN_A3Q1_image

I. Video: Steps to create and setup the FEA model in Patran

5. Trouble shooting analysis failure

"Error executing subprogram (errno) = 2"Video: What this error means and how to fix the problem
This error occurs when Nastran is not installed in the default location or when a newer version is installed than Patran. This error can however easily be corrected by following the steps in this video (Advanced users can simply edit the P3_TRANS.INI file in the Patran install folder directly to reflect the correct path to the installed Nastran executable file

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