Numerical Simulation Of Large Strain Rate Dependent J2 Problems.

Abstract

This paper discusses a constitutive model for large strain viscoplasticity implemented in a
model based on hyperelasticity. Viscoplasticity is derived in the context of Perzyna model, based on an
extended yield criteria proposed originally by Ponthot. In the paper details of large strain viscoplastic
model based on hypoelasticity, implemented in the code Metafor, are presented for comparison purposes.
The hyperelastic large strain model extended to viscoplasticity has been implemented in Sogde following
a previous work of the authors. Numerical problems in small strain case as well as large strain conditions
have been tested. Viscoplastic solutions recover limit elastic and elastoplastic cases with both codes.
The results obtained with both codes are practically identical for the small strain problem tested. For the
large strain case both codes agrees well for limiting cases, but some differences in the load level attained
for intermediate values of viscosity are found.