Coupled elasto-viscoplastic and damage model accounting for plastic anisotropy and damage evolution dependent on loading conditions

Abstract

This work presents an unconventional fully coupled elasto-viscoplastic and damage constitutive model that is suitable for investigating the failure mechanism of metallic materials. The constitutive equations are developed within a finite elastoplasticity framework under the assumption of hypoelastic-based plasticity. Anisotropic plastic potential and plastic-induced anisotropy are modelled by means of the Hill48 yield criterion and a Chaboche-type non-linear kinematic hardening law, respectively. A modified Voce-type law is assumed for the isotropic hardening behaviour. A novel law is proposed to account for an evolution of the damage depending on the loading directions. The proposed model was implemented via user subroutine for the commercial finite elements (FE) software Abaqus/Standard and used for the prediction of the cyclic failure of lead-free solder materials, the crack formation in anisotropic AISI 316L steel specimens and the description of the failure behaviour of carbon steel notched round bars and flat grooved plates.