203 非定常高速き裂進展挙動の実験力学的解析(OS6-1 コースティックス法)(OS6 実験力学の新展開)  [in Japanese] 203 Experimental Fracture Analysis of Unstable Dynamic Crack Propagation  [in Japanese]

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.