Research on Dynamic Fracture Toughness of Granite and Finite Element Analysis

In order to investigate the dynamic fracture toughness of granite,the brazilian disk specimens were subjected to diametral impact by using the splite Hopkinson pressure bar.Based on three-dimensional model of SHPB system,the test loading was introduced into Finite element model,the dynamic stress intensity factor k(t) was determined directly from the specimens at the crack tip,and then get the dynamic fracture toughness of material.The maximum average test load was substituted into the quasi-static equation to get the value of dynamic fracture toughness comparing with the results from Finite element calculation.After comparation,it is feasible to extent the quasi-static equation into dynamic situation.