Study of dynamic caustics around running interface crack tip

Based on the first invariant of stress singular field in the vicinity of running tip of an interface crack, mapping equations of the caustic curve on the reference plane and the initial curve on the specimen plane were developed. The dynamic caustics were analyzed for the crack propagating along the interface between two bonded dissimilar materials. The variations of the caustic configurations were shown with the velocity change of the running crack and the ratio change of the stress intensity factors. Two characteristic dimensions were proposed that are not only practically measurable from optical caustic contours but also suitable to represent the behavior of transient caustics.SCI(E)EI02182-1921