Hello,
I read the research report and the FORTRAN code available at https://soilmodels.com/download/vumat_umatinterface-zip/. It sounds quite interesting but I have a couple of questions about the FORTRAN code:
1- Did you have specific reasons with determining the state variables of 2 and 7, when using the following lines in the FORTRAN code? What are those state variables? and Could you put other state variables in this section of your code?
!******
!for Abaqus data check prior to analysis
if (totalTime .eq. zero) then
do km = 1, nblock
stateNew(km,2) = zero
stateNew(km,7) = stateOld(km,7)
enddo
endif
!******
2- In the part of “assignment of further variables used by umat”, you mentioned that you are not quite sure about some lines. Have you ended up with another update version of this code so far?
Thank you for your time with these questions.
Abaqus/Explicit performs a data check prior to executing the analysis, so this initial block is in place to start the analysis. Abaqus/Explicit essentially needs to establish the elastic stiffness to obtain the first estimate of the critical time increment.
A number of variables differ in naming between umat and vumat, hence these are assigned here. The coords array is not consequential for the umat.