Crack propagation in the vicinity of the interface in layered materials

The paper deals with the problem of crack propagation in the vicinity of the interface in layered materials. Layered materials are often used in practice, primarily because of their better mechanical properties in comparison with the properties of individual materials components. The configuration of a crack with its tip at the bi-material interface can be created during crack propagation in the structure. It is important to decide if the crack propagates into the second material in this case. The step change of material properties at the bi-material interface means that classical linear elastic fracture mechanics are not appropriate. A generalized approach has to be applied. In this paper, two criteria are applied for the determination of the critical value of an applied load. Knowledge of these values is important for the estimation of the service life time of such structures. The results obtained can be used especially for multi-layer polymer composites designs. On the basis of the procedures presented, suitable materials combinations can be suggested for new composite structures