Damage Formulation of Random Particulate Composites by Combined Micromechanics and Damage Mechanics

Abstract

Damage evolution of random particulate composites is formulated by the combination of two distinct theories, micromechanics and damage mechanics. Damage mechanics is applied to filler particles to describe interfacial debonding, which in turn incorporated into Mori-Tanaka's mean field theory for stiffness prediction of damaged composites. The model uses an energy balance concept to account for nonlinear behavior due to particle debonding. With this model, the effects of particle volume fraction, size distribution and interfacial strength on damage development of composites are analytically investigated. Emphasis is also placed on the effect of partial debonding which plays a dominant role for damage induced anisotropy. It is found that the model can reproduce not only stress-strain relationship but also variation in Poisson's ratio observed in damage process.