Weight Function Analysis of Interface Cracks: Mismatch Versus Oscillation

Abstract

This paper has two goals. First, it is aimed at providing a fundamental understanding of the oscillatory behavior of an interface crack between two dissimilar materials from the viewpoint of the interface mismatch that results from the cracking. Second, we extend the Bueckner-Rice weight function method to facilitate the interface crack analysis. Using properties of the surface Green’s functions of a homogeneous solid and solutions obtained from weight function formulae, a mismatch analysis is carried out which indicates that the local mismatch near the crack tip results in the oscillatory near-tip field while the mismatch on the global scale leads to the corresponding stress intensity factors. For an oscillatory interface crack field, it is shown that, other than a few extra material constants, the interface weight function analysis is completely parallel to the well-developed homogeneous theory so that knowledge of one crack solution for a given bimaterial geometry is sufficient for determination of solutions under any other loading conditions.