The objective of this proposal is to examine experimentally and numerically the inelastic effects in mixed-mode crack growths along bimaterial interfaces. Such crack growth dominates adhesive failure and fiber/matrix interfacial failure in a composite. Specifically, this study will lead to a better understanding of the reliability of adhesive joints and delamination failures of composite materials. The lack of definitive experimental data has provided the excuse for the theoreticians and numerical analysts to argue over the relative merits of their models on the interfacial crack problem for the past decade and half. This study will provide the missing data and the answers to the many theoretical conjectures. ***
