Chapter 8 - Interfacial Cracks between Two Dissimilar Solids

Abstract

For homogeneous materials, the crack tip stress and displacement fields play a central role in establishing fracture parameters for investigating interface fracture. The asymptotic eigenfunction expansion method is used to analyze the interface crack tip fields but the characteristic equations for determining the eigenvalue or the stress singularity index is much more complex due to the material property mismatch along the interface. In analyzing the asymptotic crack tip stress and displacement fields, it is sufficient to consider a semi-infinite crack lying at the interface between two dissimilar homogeneous materials. The crack surface contact zone and the stress oscillation zone near an interface crack tip are analyzed using the oscillatory crack tip fields. In addition, the oscillatory nature of stress and displacement fields near the tip of an interfacial crack implies contact of the crack surfaces. When the contact zone size is smaller than the crack length and other in-plane dimensions, such as in bimaterial cracks under Mode I loading, the oscillatory crack tip fields is used to predict interfacial fracture.