Papers by Author: Xin Wen Li

Abstract: Some problems of testing rock dynamic parameters in the SHPB experiment were analyzed and the relevant measures were proposed, which included how to determining the fracture time and the dynamic load etc. Based on the dynamic fracture experiment in the SHPB system with flattened Brazilian disc made of marble, the strain gauge technique to get the accurate fracture time was applied, and the different pulse shaper were adopted to get more precise wave data. The effective test methods of determining rock dynamic fracture toughness were discussed.

Abstract: Based on the experimental and FEM analysis, it was discussed that the stress balance was not a necessary condition for determining rock dynamic fracture toughness accurately using holed-cracked flattened Brazilian disc. The dynamic stress distribution modes of disc sample with time change were analyzed from the early loading stage to continued loading process. It was proved that the fracture time may occur before the balance of stress was achieved. It was not necessary meet the condition of the stress balance using the experiment combined with numerical method. We could get dynamic fracture toughness, according to the dynamic stress intensity factor of the crack tip and fracture time.