abaqus lecture 1

5/21/2018 Abaqus Lecture 1

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AE4131

ABAQUSLecture

Part I

Patrick [email protected]

x5-2773

Weber 201
mailto:[email protected]:[email protected]


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Overview

What isABAQUS?

Why learnABAQUS?

ABAQUSdocumentation and onlineresources

Solver structure

How to build a simple model


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What isABAQUS?

TheABAQUSsuite of software for finite elementanalysis (FEA) is known for its high performance,quality and ability to solve more kinds ofchallenging simulations than any other software.

TheABAQUSsuite consists of three coreproducts: ABAQUS/Standard,ABAQUS/ExplicitandABAQUS/CAE. Each of these packages offersadditional optional modules that addressspecialized capabilities some customers mayneed.

(From www.abaqus.com)


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What isABAQUS?

ABAQUS/Standard, provides ABAQUS analysis technology to solvetraditional implicit finite element analyses, such as static, dynamics, thermal,all powered with the widest range of contact and nonlinear material options.ABAQUS/Standardalso has optional add-on and interface products withaddress design sensitivity analysis, offshore engineering, and integrationwith third party software, e.g., plastic injection molding analysis.

ABAQUS/Explicit, provides ABAQUS analysis technology focused ontransient dynamics and quasi-static analyses using an explicit approachappropriate in many applications such as drop test, crushing and manymanufacturing processes.

ABAQUS/CAE, provides a complete modeling and visualization

environment for ABAQUS analysis products. With direct access to CADmodels, advanced meshing and visualization, and with an exclusive viewtowards ABAQUS analysis products,ABAQUS/CAEis the modelingenvironment of choice for many ABAQUS users.

(From www.abaqus.com)


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Why learnABAQUS?

Experience has shown thatABAQUSis

the easiest FEA software package to

learn.

Very good online documentation

Small learning curve which means you can

model much faster.


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ABAQUSdocumentation and

online resources

There are many online resources to help

you find solutions.

ABAQUSDocumentation

http://www.isye.gatech.edu/v6.4

Newsgroup sci.engr.analysis

ABAQUSYahoo group Engineering Computing Services

http://www.ecs.gatech.edu
http://www.isye.gatech.edu/v6.4http://www.isye.gatech.edu/v6.4


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Solver Structure

Standard

Command

lineABAQUS

CAE


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How to build a simple model

All models are called input files. An input filehas two sections; Modeland History

The Modelsection contains all the information

about the model and comes before the history

section.

The Historysection is what you do to the model.

You work on the model in Steps.

Input files have a .inpextension and can becreated in any ASCII (text) editor.


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Beam example

20,000 lbs

Steel beam, Youngs modulus 30x106 lbs/in2

Length 100 inches, width = 1 inch, height = 2 inches

x, 1

y, 2


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Beam example

I want to know stresses and strains along

the x-direction and the forces and moments

in each section of the beam due to a static

load.


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Sketch out your FEA model

20,000 lbs

x, 1

y, 2

1 2 3 4 5

61 2 3 4 5

Nodes

Elements


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ABAQUS has a large library of elements

(From ABAQUS documentation)

Ill pick B312-node linear beam

Pick your elements


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Simple Input file (Modeldata)

*HEADING

CANTILEVER BEAM**

** This is in inches

**

*NODE

1, 0.

6, 100.

*NGEN, NSET=allnodes

1, 6

*ELEMENT, TYPE=B31

1, 1, 2

*ELGEN, ELSET=BEAM

1, 5

*BEAM SECTION, SECTION=RECTANGULAR, ELSET=BEAM, MATERIAL=STEEL1., 2.

*MATERIAL, NAME=STEEL

*ELASTIC

30.E6,

*BOUNDARY

1, ENCASTRE


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Simple Input file (HistorySection)*STEP, PERTURBATION

*STATIC

**

** The load is in pounds

**

*CLOAD

6, 2, -20000.

*EL PRINT, POSITION=AVERAGED AT NODES, SUMMARY=YES

S11, E11SF,

*NODE FILE, NSET=allnodes

U, CF, RF

*OUTPUT, FIELD, VARIABLE=PRESELECT

*ELEMENT OUTPUT

SF,

*OUTPUT, HISTORY

*NODE OUTPUT, NSET=allnodes

U, CF, RF

*END STEP


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To runABAQUS

At the command lineabaqus job=filename

Use the Input Filefilename

WITHOUT the file

extension (.inp)


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The resultsYou will get many files after your job is complete.

.dat Contains results information you can read. Veryimportant for debugging.

.fil Only for the computer

.com Only for the computer

.odb Only for the computer but will be used by CAE

.msg Contains information you can read about how the

job ran. Can be important for debugging.

.prt Only for the computer

.sta Contains information you can read about the status

of the job while running

.log Contains information you can read about how the

job ran. Can be important for debugging.


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A truss problem

200 lbs

100 lbs

x, 1

y, 2

Steel truss segments, Youngs modulus 30x106 lbs/in2

Diameter of each truss is 1 inch

20 in.

20 in.


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Beam example

I want to know stresses and strains in all

truss segments due to the static loads

shown in the figure.


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Sketch out your FEA model

x, 1

y, 2

Steel truss segments, Youngs modulus 30x106 lbs/in2

Diameter of each truss is 1 inch

1 2 3 4 5 6

7 8 9 10 1112

1 2 3 4 5

6 7 8 9 10

11 12 13 14 15

161718 19 20


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(From ABAQUS documentation)

Ill pick T3D22-node linear displacement

Pick your elements


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ModalSection*HEADING

CANTILEVER BEAM

**** This is in inches

**

*NODE

1, 0., 0.

6, 100., 0.

7, 0., 20.

12, 100., 20.

*NSET, NSET=FIXED

1, 7

*NGEN, NSET=allnodes

1, 6

7, 12

*ELEMENT, TYPE=T3D2, ELSET=BEAM

1, 1, 2

2, 2, 33, 3, 4

4, 4, 5

5, 5, 6

6, 7, 8

7, 8, 9

8, 9, 10

9, 10, 11

10, 11, 1211, 1, 8

12, 2, 9

13, 3, 10

14, 4, 11

15, 5, 12

16, 6, 12

17, 2, 8

18, 3, 9

19, 4, 10

20, 5, 11

*SOLID SECTION, ELSET=BEAM,

MATERIAL=STEEL

1.,


*ELASTIC30.E6,

*BOUNDARY

FIXED, ENCASTRE


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HistorySection

*STEP, PERTURBATION

*STATIC

**

** The load is in pounds

**

*CLOAD

6, 1, 200.12, 2, -100,

*EL PRINT, POSITION=AVERAGED AT NODES, SUMMARY=YES

S, E

*NODE FILE, NSET=allnodes

U, CF, RF

*OUTPUT, FIELD, VARIABLE=PRESELECT

*ELEMENT OUTPUTS, E

*OUTPUT, HISTORY

*NODE OUTPUT, NSET=allnodes

U, CF, RF

*END STEP


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Looking at the resultsfiles

Starting with the .logfile you should review

the results files.


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Models with continuum elements

To model most 3D structures that are

bending Continuum or brick elements are

the best.

Each element requires any nodes.

Models can be made by hand rather than

CAE but can take much longer.


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Continuum Elements


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3D Cantilever Beam Model data

*HEADING

cantilever beam**

** Coordinates are in

inches

**

*NODE

1, 0.,0.,0.193, 0.,0.,24.

1601, 2.,0.,0.

1793, 2.,0.,24.

8001, 0.,0.5,0.

8193, 0.,0.5,24.

9601, 2.,0.5,0.

9793, 2.,0.5,24.

**

** Create nodes for beam

***NGEN,NSET=FIX1

1,1601,200

*NGEN,NSET=FIX2

8001,9601,200

*NFILL,NSET=FIX

FIX1,FIX2,4,2000*NGEN,NSET=END1

193,1793,200

*NGEN,NSET=END2

8193,9793,200

*NFILL,NSET=END

END1,END2,4,2000

*NFILL,NSET=CBEAM

FIX,END,192,1

**

*NSET, NSET=SENSOR

8993


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Model section (cont.)**

** Make master elements for beam

**

*ELEMENT,TYPE=C3D20R

1, 1,401,4401,4001, 5,405,4405,4005, 201,2401,4201,2001,205,2405,4205,2005, 3,403,4403,4003

**

** Create elements for beam

**

*ELGEN,ELSET=CBEAM1,4,400,1,48,4,10,2,4000,2000

*ELSET, ELSET=LOCSTRESS

2,3,12,22,32,42,52,62,13,23,33,43,53,63,2002,2003

2012,2022,2032,2042,2052,2062,2013,2023,2033,2043,2053,2063

**

** Material properties for steel

**

*SOLID SECTION, MATERIAL=STEEL, ELSET=CBEAM


**

** Youngs modulus is in lbf/in^2

**

*ELASTIC

29.E6,0.3

**


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Student Accounts

Now you are ready to work the projects.

You can use your AE student account in

the AE Computer Lab (Knight 318) to runABAQUS on these systems.

Or you can get an account on the ECS

network (go to http://www.ecs.gatech.edu)

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