Study of Dynamic Branching Fracture by Numerical Simulation
Toshihisa NISHIOKA, Stanislav TCHOUIKOV and Takehiro FUJIMOTO
Abstract:Dynamic branching fracture phenomena are often observed in brittle materials. Prediction of such fracture path is extremely important not only for academic interest, but also to prevent catastrophic failure of structures and to establish a safety design methodology. In previous studies, we elucidated the governing condition of dynamic branching fracture phenomena from experimental results, and also succeeded the generation-phase simulation for dynamic branching fracture. In this study, we develop a fracture-path prediction simulation method for dynamic branching fracture phenomena. In these simulations, the dynamic fracture mechanics parameters for shortly bifurcated cracks are accurately evaluated by a switching method of the path independent dynamic J integral. By using the maximum hoop stress criterion and the local symmetry criterion, the fracture-path prediction simulations are carried out. The results of both prediction theories excellently agree with the experimentally observed actual fracture paths. Key Words:Dynamic crack bifurcation, Fracture path prediction, Dynamic J integral, Moving finite element method, Delaunay automatic mesh generation, Critical energy flux criterion