Applicability of lnclined Strip Yield Superdis10catiOn IV10del to Crack Problelms

The approach that the macroscopic plasticity at a crack tip can be considered in terms of dislocation arrays was first introduced by Bilby, Cottrell and Swinden (BCS model)l). Shortly thereafter, Bilby and Swinden2) generalized this approach to permit the dislocation slip plane to be inclined to the crack plane. The work of Atkinson et. al.3) circumvented the mathematical difficulties in the inqlined strip yield model by introducing the idea of a superdiSlocation to represent the net effect of the dislocation array. In this report, this approach is extended to study the plasticity at an interface crack between the dissimillar materialS. 2. The Problem A crack of length 2a along the interface, with a remotely applied stress o acting normal to the crack plane, is considered. It will suffice to describe the location (h,, 0t) and the strength b1 of the superdislocation on the right tip due to the symmetry (see Fig. 1). Here the index )u:I andZ and denote the upper half-plane.!+ and the lower half-plane S-, respectively. The stress and displacemen! fields for the inclined strip yield superdislocation model are obtained by superposition using the solutions for the follwoing subproblems