Effective elastoplastic behavior of two-phase ductile matrix composites: A micromechanical framework

A micromechanics-based framework is presented to predict effective elastoplastic behavior of two-phase particle-reinforced ductile matrix composites (PRDMCs) containing many randomly dispersed elastic spherical inhomogeneities. Specifically, the inclusion phase (particle) is assumed to be elastic and the matrix phase is elastoplastic. A complete second-order formulation is presented based on the probabilistic spatial distribution of spherical particles, pairwise particle interactions and the ensemble-volume averaging procedure. Two non-equivalent formulations are considered in detail to derive the effective yield functions. In addition, the plastic Bow rule and hardening law are postulated according to continuum plasticity and, together with the micromechanically derived effective yield function, are employed to characterize the plastic behavior of PRDMCs under three-dimensional arbitrary loading/unloading histories. Initial effective yield criteria for incompressible ductile matrix containing many randomly dispersed spherical voids are also studied. Furthermore, uniaxial elastoplastic stress-strain behavior of PRDMCs is investigated. Comparison between our theoretical uniaxial stress-strain predictions and experimental data for PRDMCs is also performed to illustrate the capability of the proposed framework. Copyright (C) 1996 Elsevier Science Ltd.