A large strain thermodynamically-based viscoelastic-viscoplastic model applied to two-dimensional finite element analysis of solids

Resumo

In this work, we propose a large strain viscoelastic-viscoplastic constitutive model applied to two-
dimensional finite element analysis of solids. The model is developed in a thermodynamic framework, based

on the multiplicative decomposition of the deformation gradient into elastic, viscous and plastic components.
The viscoelastic part is represented by Zener’s rheological model, and is formulated with an internal variable
approach, with evolution law in terms of the viscous deformations gradient rates. For the viscoplastic part, we
apply a Perzyna-like model, including a large strain generalization of the classical Armstrong-Frederick kinematic
hardening. In order to characterize the proposed constitutive model, we present results of uniaxial relaxation and
creep tests under different analysis conditions, as well as more complex examples showing the potentialities of the
developed framework.