A micromechanical model for ductile porous composites with debonding damage

摘要

This paper is devoted to micromechanical modeling of the overall elastoplastic behavior and damage evolution in clayey rocks. The studied material is composed of a porous matrix which is embedded by linear elastic mineral inclusions. The solid phase of porous matrix is described by a pressure sensitive plastic model with a non associated flow rule. With a two-level homogenization procedure, the macroscopic plastic criterion of the heterogeneous material is deduced and takes into account effects of pores and mineral inclusions. Then it is assumed that the material damage is related to progressive debonding of mineral inclusions. The Weibull's statistical function is used to describe the varying probability of inclusion debonding. Finally, the proposed micro- macro model is applied to describe the macroscopic behavior of a typical clayey rock. Comparisons between the numerical results and experimental data show that the proposed model is able to capture the main features of the mechanical behavior of the studied material.