ABAQUS VUMAT for the Neo-Hookean model - input files

[Jorgen]

This zip-file contains a couple of different ABAQUS/Explicit input files that can be used to test the vumat for the Neo-Hookean (NH) model (vumat_nh.f).

[cardiffben]

Could you tell me where to download vumat_nh.f file?

Ben

This zip-file contains a couple of different ABAQUS/Explicit input files that can be used to test the vumat for the Neo-Hookean (NH) model (vumat_nh.f).

[Jorgen]

You can download the vumat_nh.f file here.

- Jorgen

[cardiffben]

Dear Dr. Jorgen

Could you tell the exact form of the strain energy function you used in this VUMAT?

many thanks,
ben

[Jorgen]

I used the following strain energy density:

[cardiffben]

Dear Dr. Jorgen

I programmed the UMAT for the neo-hookean model using the same strain-energy function as you adopted in VUMAT.
My aim is to compare the results. However, my UMAT does not converge. Do you know what is the possible reason for that?

Many thanks,
ben
postgraduate student
Cardiff University

[Jorgen]

It might be related to the Jacobian matrix. Have you tried to run it with a linear elastic Jacobian?

- Jorgen

[vansyle]

Dear Dr. Jorgen,

I tried to inport your input file, but i only received a message:
"The model "case01_ABAx" has been created.
WARNING: The input file contains one or more data items which have been parameterized. Parameterized input files can not yet be imported into Abaqus/CAE. This occurred while scanning input file for parameterized data. The input file will not be imported."

I am using Abaqus v 6.7-1. Maybe this problem because of different version?

Best regards,

[Jorgen]

You should be able to run the input file from an Abaqus command prompt window. For this simple example there is no need to import the inp-file into CAE.

Or alternatively, remove the parameters in the inp-file and then import into CAE.

- Jorgen

[jad]

This zip-file contains a couple of different ABAQUS/Explicit input files that can be used to test the vumat for the Neo-Hookean (NH) model (vumat_nh.f).

thank you doctor jorgen, for your help , i'm going to test the this subroutine ,

and i will give my feedback soon.

thanks a lot for your supprt

all kinds regards ,

jad