Dynamic Fracture Experiment of Fractured Rock under Dynamic Loading

Table 2

Crack propagation process of Specimen c1 at the loading rate of 9.7 m/s.

High-speed images	Crack sketch	Stress (MPa)	Loading time (μs)	Crack propagation process
		20.82; Prepeak	27.9	Cracks began to occur from the middle of prefabricated fracture of the specimen
		26.44; At peak	71.9	Cracks continued to propagate
		17.44; Postpeak	123.7	Cracks propagating from the middle of fracture extended and connected through the entire specimen, with increasing width of cracks