Constitutive Equations and Numerical Approaches in Rate Dependent Material Formulations

Abstract

The classical Duvaut-Lion and Perzyna formulations for rate dependent constitutive models were recently extended by different proposal to allow a more convenient and efficient numerical treatment in computational simulations of viscoplastic or viscoplastic-damage material proceses. The main goal was the development full consistent formulations
so that the well known numerical approches developed for rate independent material models can be still.
This paper focuses on the description of alternatives formulations of rate dependent constitutive equations and on the numerical methods associated with each other. In this regard the fourth order material operators are developed and
the features of the performance of diffuse and localized failure indicators are analyzed.