A micro-macro model for porous geomaterials with inclusion debonding

This paper is devoted to micromechanical modeling of the overall elastoplastic behavior and damage evolution in ductile porous geomaterials. The studied material is composed of a porous matrix that is embedded by linear elastic mineral inclusions. The solid phase of porous matrix is described by a pressure sensitive plastic model with a nonassociated flow rule. With a two-level homogenization procedure, the macroscopic plastic criterion of the heterogeneous material is deduced and takes into account the 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. The debonded inclusions are considered as completely separated from the matrix and regarded as voids for simplicity. Finally, the proposed micro-macro model is applied to describe the macroscopic behavior of claystones. 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.