Interfacial debonding around rectangular features in multilayer structures

This article describes a numerical approach for predicting debonding in multi-layers comprised of rectangular features of different sizes. A single global meshing strategy for finite element analysis is described that includes focused radial meshes at every material junction to accurately capture crack tip and material junction singularities. The strategy is designed to allow straightforward yet accurate calculations of energy release rates for steady-state interfacial debonding in complex architectures. Guidelines for meshing parameters ( such as element density and distribution) are discussed on the basis of convergence studies of stress distributions along interface junctions, crack opening displacements and crack driving forces along interfaces. The utility of the approach is demonstrated via a study of debonding around rectangular inclusions, which illustrates relationships between energy release rates, inclusion aspect ratio and elastic mismatch. The paper concludes with an illustration of how interfacial debonding along finite-sized features can promote cracking in adjacent layers.