I am implementing an isotropic J2 plasticity UMAT in CalculiX.
When I print the PROPS matrix on command window using write(,) command of FORTRAN, it shows only ZEROS (image attached).
I checked my .inp file also, and data is entered correctly (image attached).
I also tried changing the case of PROPS to props but still the same.
I explicitly defined EMOD, ENU, SYIELD in UMAT preamble part, but still the same.
Don’t know what is it that I am missing.
Can someone please help?
Everything that I can see here looks good. Did you change the lines 550 - 557 in umat_abaqusnl.f? Also, could you print the values of the variable elconloc in this file? This may give us an idea of what’s going on.
I would have to take a closer look at the J2PLAS subroutine but I would start by having a simple unit test and continue to debug it in the way you are doing, step by step. Maybe use gdb to debug as it runs - this way may be faster than printing statements.