Thanks for your reply. Yes the hyperelastic umat includes a model for fatigue induced damage and permanent set, so the in built models are not suitable.
I'm using a fortran code which acts as an interface between a VUMAT and UMAT, so that a UMAT can be used in a dynamic simulation. The interface code can be found here: https://soilmodels.com/download/vumat_umatinterface-zip/, where the VUMAT calls the UMAT and re-orders tensors into the required...
Thank you for your replies- I haven't tried the automatic stabilization so that might work. I've also used up to 4 elements through the thickness and it doesn't help with convergence.
Yes I have checked that the UMAT is correct- the material model is a HGO an it matches the result from using...
I am doing simulations of a cyclic pressure applied to a surface of a circle. The model is a quarter model of a circle, with the pressure applied in the z-direction, the thickness is 0.4 mm and diameter 20 mm, where the material is a user subroutine of a hyperelastic matrix-fibre composite...
