A bi-material or bi-layer structure is increasingly used in various engineering applications, such as thin film coating, piezoelectric materials, composite laminates and sandwiches, adhesive joints, concrete structures strengthed by FRP, etc. However, interface fracture or interlaminar delamination is one of the most common failure modes in this type of layered structures. In general, damage mechanics(stress-based methods) is used to predict the initiation of delamination, followed by fracture mechanics whi...