Boundary Element Modeling of Crack Propagation Path in Brittle Matrix Composites Reinforced by Short Rectangular Particulates

Abstract

Interaction between a crack and a rectangular particulate in a single edge notched beam is simulated using a boundary element program of automatic crack extension. The stress intensity factors of the growing crack are obtained from the J-integral. Three crack extension paths: deflecting around the particulate, growing along the interface and penetrating into the particulate are achieved in terms of the mismatch state of mechanical characteristics of matrix and particulate. The toughening is also given by the ratio of stress intensity factors. The results reveal that as stress shielding occurs, large toughening is obtained when the crack is approaching to a stiff and strong particulate weakly bonded to a relatively soft matrix; inversely the soft particulate is functional to attract the crack tip toward it, and obvious toughening arises when the tip is within this soft particulate. The present work intends to help for the design of particulate reinforced composites.