Hello,

I am modeling a plate-like specimen made out of a fiber composite laminate. I have assigned a general shell stiffness section to this model. I need to modify the bending stiffness matrix (D) of this stiffness matrix according to the strain at each integration point at each increment. The strain will act as the field variable, and I have a non-linear relation between the strain and ABD matrix variation (Basically I have ABD matrix for different strain values). How can I achieve this using a subroutine or any other method?

Thank you very much.