problem during UMAT subroutine compilation

[Paul_S]

Hello,

can anybody give me any practical advice how to use VUMAT subroutine for ABAQUS? I am a really beginner in this area and I tried to use the VUMAT example from this website (neo-hookean material). However an error occured: something with "df.exe" file .... probably during compilation of the VUMAT. Should I install some FORTRAN compiler? Or is it necessary to compile the VUMAT subroutine separately before the task is ABAQUS is submitted?

Thank you for your advice, Paul.

[Jorgen]

Creating a UMAT or VUMAT subroutine is a very difficult task, but using an existing subroutine should be easy - as long as you have the necessary compilers on you computer.

The df.exe file that you mentioned is the Fortran compiler for Windows PCs. If you want to compile a user subroutine for use with a FE software then you need an appropriate compiler installed. I recommend that you use exactly the compiler and version that your FE program recommends.

For ABAQUS and Windows PCs this is either the old Digital Fortran (df) compiler, or the new Intel Fortran compiler (ifort).

You can use your VUMAT subroutine by using the following command:
abaqus job=[jobname] user=[fortran_file_name]

There are also other ways to compiler a subroutine, see the ABAQUS manuals for more info.

- Jorgen

[Paul_S]

Thank you for your reaction. OK - I will try to download proper fortran compiler and link it to ABAQUS. Nevertheless I am still not sure if I use the VUMAT suboutine correctly. Can anybody approve me the following procedure:

1/ First I specify the input file ("case01_ABAx.inp" downloaded from this web page) through the following dialog window:
"JOB/JOB MANAGER/CREATE/SOURCE:INPUT FILE"

2/ Then I specify the VUMAT soubroutine file ("vumat_nh.f" downloaded from this web page) through the following dialog window:
"JOB/JOB MANAGER/EDIT/GENERAL/USER SUBROUTINE FILE:"

(moreover, previously I have to re-name the *.f file to *.for extension because of ABAQUS warning message durring an attempt to specify *.f file as a user subroutine file)

3/ Submit the job

Is that procedure correct? Thanks for your focus.
Paul

[Jorgen]

Your description sounds right.

Note: The Fortran file needs to end with .for for Windows computers, and .f for Linux and Unix computers.

- Jorgen