A hardening orthotropic plasticity model for non‐frictional composites: Rate formulation and integration algorithm

Abstract

Abstract The rate formulation and an unconditionally stable integration algorithm for a single‐surface hardening anisotropic elastoplasticity model are developed to obtain an effective medium constitutive model for a class of periodic elastoplastic composites. Because the plasticity model features an intrinsically anisotropic failure criterion and hardening law, it requires more material parameters (15) than does its isotropic analogue (2). To address this issue and to assess how well the new model serves as an effective medium constitutive model for a class of composites, results from numerical elastoplastic homogenization computations are utilized for free‐parameter estimation. It is shown that the new model provides a good fit to the homogenization data, and the model's excellent performance in a two‐dimensional finite element setting is demonstrated by performing computations involving in‐plane loading of an elastoplastic masonry wall. The wall is modelled first as a heterogeneous medium with all of its microstructure, and subsequently as a homogeneous effective medium with the new plasticity model.