抄録
Dynamic crack propagation in PMMA was studied using the method of caustics in combination with a Cranz-Schardin type high-speed camera. Three different types of specimen geometries were employed to achieve the crack acceleration, deceleration and/or re-acceleration process in one fracture event. Dynamic stress intensity factor K_<ID> and crack velocity a were evaluated in the course of crack propagation to obtain the relationship between K_<ID> and a. The effect of crack acceleration and deceleration on the K_<ID>-a relations was examined.
