Void/Bridged-Crack Interactions and Their Implications for Defect Coalescence

Abstract

Void-crack interactions with crack bridging play an important role in the determination of rupture failure modes of composite materials. In this paper, an integral equation approach is developed to study the behavior of systems containing multiple in teracting voids and cracks with a general form of crack bridging. The formulation is based on a superposition technique that decompose the interacting voids and cracks into a number of subproblems, each involving only a single void or single crack. The integral equations are fully non-singular and thus can be solved effectively with a Gauss integra tion scheme. Numerical examples are given in order to study the effects of bridging, bridg ing anisotropy, void size, and void spacing, among others, on the crack-tip behavior. The influence of void-crack interactions on the fracture path are also investigated. For a material containing doubly periodic collinear holes arranged with offsets in subsequent rows, it is found that the fracture path can be formed either by the coalescence of the holes in a row or by the coalescence of the holes across neighboring rows, depending on the ratio of vertical to horizontal void spacing.