Implementation of an orthotropic elasto-plasticity model with advanced kinematic hardening rule

Abstract

An elasto-plasticity material model is proposed to simulate the behavior of orthotropic materials under cyclic loading modes. The model makes it possible to simulate the multiaxial ratcheting effects and is implemented into finite element analysis software Abaqus through the subroutine UMAT. The elasticity is considered linear and is described by Hook's law for an orthotropic material. The used plasticity model is based on Hill's yield function, and the kinematic hardening rule combined with an isotropic hardening rule is included. An explicit discretization scheme of forward Euler type is applied to integrate the initial value problem. The infinitesimal strains framework is assumed and additive decomposition of total strain is performed. The derived incremental problem is solved by a two-step numerical algorithm of the predictor-corrector type. Finally, the numerical example for cycle loading is presented.