Cracking and Debonding on Bimaterial Interface under Uniform Loading

Abstract

A problem is solved for a bimaterial plane that consists of partially bonded dissimilar half‐planes subject to uniform traction parallel to the interface at infinity. Fracture conditions at a debonded tip are investigated, i.e., a crack initiation into a material and/or the debonding propagation along the interface. A crack initiation is specified by the following three conditions: (1) Stress distribution before a crack initiation; (2) stress‐intensity factor for opening mode immediately after the crack initiation; and (3) energy release rate for the crack. The debonding propagation is specified by the following two conditions: (1) Stress distribution before the crack initiation; and (2) energy release rate for the debonding. There are chances at the same time that both the crack and the debonding may occur and/or that two cracks may initiate into both two materials. However, one phenomenon of the failure must occur in general at the debonded tip. In these cases, the fracture phenomenon is evaluated and specified by their energy release rates in comparison with their critical ones for the crack and the debonding. Stress distribution after the crack initiation is evaluated by the solution for the symmetrical shape with the same crack lengths at an end of the bonded interface in each material.