Dynamic caustics analysis of crack in samdwich materials under blasting stress wave

Transitive dynamic caustic model experiments were used with a transparent birefringence material in the dynamic caustic measuring system. The propagation of cracks in samdwich materials was recorded. It was observed that the direction of a crack propagation removes some distance from the initial one after it has crossed a samdwich. The time-dependent relations of the dynamic stress intensity factor at crack tip were showed. Analyzed the crack propagation mechanism in samdwich materials under blasting stress wave and the effects of the joint to stress wave. By the blasting stress wave theory, the result was obtained that the crack initiation mechanism is difference between the crack in the samdwich and behind of it. The experiment supplied a new method of studying the blasting mechanisms of directional broken blasting.