I highly appreciate anyone who takes a look at my questions and responses them...
I am beginner in using UPFs. I have red UPF's manual and USERMAT3D subroutine.
first of all, Recently, i have written my desired user material subroutine, which contains stress update(3 mode is considered using RMA:apex return mapping, line return mapping and surface return mapping), and material constitutive matrix. Now, i want to know if there is any other variable , which should be calculated? (i mean: Should the value for epesq and the other materials presented in USERMAT3D be calculated and written?)
moreover, is not there any problem with using a significant number of subroutines, which are to be called in the main part of USERMAT3D?(I have previously heard about some problems about using multiple routines in an user-defined routine...).
above all, I am a bit confused about verification process for validating my code...in fact, I don't know how i can test my code...(I think, testing a single element for a linear elastic material which is recommended for verifying the linking and activating procedure can not efficiently evaluate the code's accuracy in the case of material's plastic behavior). Is there any useful and well-prepared procedure for verifying an user material code?
thanks a lot for paying attention to my questions and for any probable response.
With The Kindest and Warmest Regards, Hadi