Dynamic Fracture Experiment of Fractured Rock under Dynamic Loading

Table 7

Crack propagation process of Specimen b3 at the loading rate of 11.4 m/s.

High-speed images	Crack sketch	Stress (MPa)	Loading time (μs)	Crack propagation process
		34.18; Prepeak	69.8	Microcracks propagating to the left and right directions occurred from the vertex of the prefabricated fracture of specimen
		42.09; At peak	104.4	Cracks began to occur from the middle of the specimen fracture, and cracks began to occur near the left-end face
		33.68; Postpeak	139.3	Cracks continued to propagate with increased width, and more cracks covered up the surface of the specimen