Overall elastoplastic damage responses of spherical particle-reinforced composites containing imperfect interfaces

As a predominant damage mode, the interfacial damage between the reinforcements and the matrix is of importance for the composite materials. Correspondingly, in this paper, the effects of imperfect interfaces are systematically investigated in the framework of higher order micromechanics and homogenization. To examine the effects of imperfect interfaces, the equivalent stiffness of reinforcing particles is considered based on the spring interface model. By taking advantage of the equivalent stiffness, the effective stiffness and the effective yield function of a composite are systematically derived to study the overall elastoplastic damage behaviors of particle-reinforced composites. In the absence of damage, comparisons between the theoretical predictions and the available experimental data are presented to illustrate the predictive capability of proposed micromechanical framework. Subsequently, a series of parametric studies are performed to examine the characteristics of the proposed micromechanics-based damage formulation.