Dynamic Crack Curving and Branching in Line-Pipe

Abstract

The newly derived dynamic crack curving and crack branching criteria are briefly reviewed. The two criteria are justified by a micro-mechanics model and are used to predict crack curving and crack branching of dynamic photoelastic experiments involving Homalite-100 fracture specimens. The latter crack branching criterion requires as a necessary condition a critical dynamic stress intensity factor, Klb , which is accompanied by a sufficient condition involving the former crack curving criterion. This criteria is further verified by a dynamic finite element analysis of a bursting steel pipe of Congleton [26] and Almond, et al. [27], where the numerically computed branching stress intensity factor and branching angle are in good agreement with experimental results.