Damage Micromechanics for Constitutive Relations and Failure of Microcracked Quasi-Brittle Materials

This article addresses several issues in damage micromechanics for microcracked brittle or quasi-brittle solids, with major attention paid on summarizing some recent works of the present authors. First, we discuss the methods for characterizing evolutionary damage of microcracks and introduce the concept of orientation domain of microcrack growth. Second, we describe how to calculate the macroscopically effective constitutive relation of microcracking solids under complex loading. Third, the effective medium or effective field methods for estimating the effective elastic moduli of microcracked solids are formulated into a universal framework. Fourth, a subregion method is suggested to calculate the effective elastic moduli, fracture strength, and failure process of solids containing a large number and/or a high density of microcracks. Additionally, this method is combined with the finite element method to simulate the damage evolution and failure process of engineering structures.