How to use a UMAT 1

[ftiphain]

Hello, I will have to use a UMAT. - it would be possible that somebody indicates the procedure to me to make use of it? Thank you in advance.

 

[Drej]

Do you mean how to write a UMAT, or how to use an existing UMAT?

If you mean the former then there is no way on God's green earth that this -- or any other -- forum will help you to the extent of providing a step by step procedure. Go speak to ABAQUS about it (and even by their own admission they don't fully understand them). If you mean the latter, then the ABAQUS documentation has a very good section on using UMATs.


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[ftiphain]

I mean how to use an existing UMAT ?

 

[Drej]

Linking the UMAT with the user's ABAQUS run is done through the standard ABAQUS command line:

abaqus j=jobname user=umat.o

The ABAQUS input file will contain the material parameters. Including these parameters is done through the *USER MATERIAL keyword in the input file:

--------------------------------------------------------------------------------
*HEADING
Test
*NODE
1, 0.0, 0.0, 0.0
2, 1.0, 0.0, 0.0
3, 1.0, 1.0, 0.0
4, 0.0, 1.0, 0.0
*ELEMENT,TYPE=CPS4,ELSET=ONE
1,1,2,3,4
*SOLID SECTION,ELSET=ONE,MATERIAL=FIRST
*MATERIAL,NAME=FIRST  
*DEPVAR
80
[b]*USER MATERIAL,CONSTANTS=29[/b]
1,3,1.5E5,0.33,90000.,100.,5.5221,0.1E+22,
90.44,32.71728773,50.6474693,4.000,0.10E+01,3142132918629.0,0.10E+22,1.99939
2.019,1.993,4.3444,1.7660,2.91162,0.49955D-03,0.499684D-03,0.5D-D03
67030.5,33793.86,1835.45953,0.0, 0.0  
*BOUNDARY
1, 1,2
2, 2
4, 1
.

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[ftiphain]

ok thank u