[AbaqusUMATStress] How to initialize state variables (STATEV) in the input file?

[SongHaoqi2001]

Hello MOOSE community,

I am currently using the AbaqusUMATStress material to interface with a UMAT subroutine for my simulation.

I have successfully linked the UMAT, but I have encountered an issue regarding the initialization of state variables (STATEV). I checked the documentation for AbaqusUMATStress and found the num_state_vars parameter, which allows me to define the number of state variables. However, I could not find a specific parameter or method to set the initial values for these state variables (similar to *INITIAL CONDITIONS, TYPE=SOLUTION in Abaqus).

My Question: Is there a direct way to set the initial values of STATEV within the MOOSE input file (e.g., in the [Materials] block)? Or is the recommended workflow to handle initialization entirely within the UMAT code (e.g., detecting if KSTEP==1 or TIME==0)?

Any suggestions or examples would be greatly appreciated.

Thank you!

[dschwen]

Haoqi, I missed this question. What did you arrive at? My suggestion would be to handle this in your umat, just like we let individual materials handle their stateful property initialization.

[ngrilli]

I don't think there is a way to set the initial values of STATEV within the MOOSE input file,
but you can easily modify AbaqusUMATStress::initQpStatefulProperties()
to initialize _state_var[_qp][i] to a custom value instead of zero.

KSTEP is not updated as far as I can see in AbaqusUMATStress,
you probably better use KINC for detecting the first time step.