Abstract
Branched cracks are often observed in brittle materials and structures. However the mechanism of crack branching is not fully clarified. In this paper, first, dynamic crack branching phenomena in Homalite-911 and Homalite-100 were experimentally investigated. Caustic patterns during dynamic crack branching were recorded by an ultrahigh-speed camera. Next, on the basis of the dynamic J integral, energy concepts for dynamic crack branching are presented. Special attentions are focused on the energy flow into dynamically propagating crack tips. Then four possible fracture parameters associated with the dynamic J integral are proposed. The dynamic J integral values in a dynamic crack branching test are directly evaluated by the caustic patterns taken by the high-speed camera. The variations of four fracture parameters during dynamic crack propagation including at the instant of crack branching are presented. The experimental results reveal that the energy flux per a unit time into a propagating crack tip governs the crack branching.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
