Our group has been working hard for the past three months to figure out how to implement a large strain viscoelastic material model in AUTODYN. We are all new to using AUTODYN/ANSYS. I know that ABAQUS supports a user subroutine UMAT where the user can write his/her own code to give a fourth order modulus tensor as an input. Is there such a feature in AUTODYN? All that I get to see is a few subroutines such as usrstr.f90, usrero.f90 etc. In usrstr.f90, one can give only the flow stress equation, which is relevant for elasto-plastic materials. Ours is a rate dependent elastomeric material, which needs both hyperelasticity and viscoelasticity.nnCan one of you please help us?n