How can I use a UMAT subroutine in Abaqus?

[ab110]

Hi,

It is the first time that I want to use a UMAT subroutine in Abaqus. I have a Umat subroutine which is written by FORTRAN (*.f). To use the subroutine I have chosen user define in material and I wish to select the subroutine file when I wanted to define the job. But I could not select this file and I got the error “the subroutine should have *.for format”). What does it mean and how can I use UMAT in Abaqus? Does anyone have a Umat example to put here that I can use that in Abaqus 6.9?

C,
A

 

[DanStro]

Just change the file extension to .for and it should allow you to select it. I don't understand why there is a need to do this but on the very few occasions I've used subroutines they have run fine with just the change.

HTH,
Dan

 

[MechIrl]

With the usual setup .for is for windows machines while .f is for unix.

 

[ab110]

Thanks for your help.