UMAT from stress strain in multiscale modeling

You can create a material model from stress-strain data if you select to use a simple material model, like linear elastic, Marlow, elastic-plastic.
It is indeed more difficult to do that for general material response!

-Jorgen

Dear Dr. Bergstrom,

Thank you very much for your reply. I was wondering if I can create a UMAT with a general material response. And I have a question: for example say I have a general material stress-strain curve with an increasing non-linear elastic part followed by a non-linear softening part and this behavior is periodic (as shown in the picture, but with the same peak for example), how can I simulate that behavior? Can I create my own material model for that?Hope its clear.

Thank you very much for your time

Best regards

Material models are usually created based on insight into the micromechanisms creating the macroscopic response.
What material are you studying?

Does your figure show stress relaxation behavior, damage, or something else?

-Jorgen

Dear Dr. Bergstrom,

Yes the figure shows relaxation behavior in polymeric structures and I was wondering if it is possible to create a UMAT for that particular trend of stress-strain curve.
Thank you very much for your help,

Best regards

I have developed a number of UMATs that can capture that type of response. So it is certainly possible.

-Jorgen