[Stjepan]

Hello to everyone.

I am working on a research for my PhD that would require writing user defined hyperelastic material models and user defined finite elements. I have already done writing several user defined material models with UserHyper subroutine, which is relatively easy as one of the examples is already provided and can be used for reference.

However, writing user elements with UserElem subroutine is much harder for me, since the example provided wth Ansys installation is to be used only with linear analysis and, not having previous experience with writing user defined finite element models in Ansys, I don't even know how to adapt the existing example in order to work with non-linear analysis (nlgeom=on). I am interested if anyone here had any experience working with it and is willing to share it.

Thanks in advance.

[Stjepan]

Is there anyone that can help, please?

I am mostly concerned with this part of the code, as it explicitly states it is defined only for linear analysis:


IF (nlgeom.EQ.0) THEN
DO iDim = 1, 3
DO iDim1 = 1, 3
defG0(iDim, iDim1) = 0.0D0
END DO
defG0(iDim, iDim) = 1.0D0
END DO
CALL vmove (defG0(1,1),defG(1,1),9)
ELSE
c Nonlinear logic not defined here
END IF