Dynamic Behavior Analysis of Perforated Crack Propagation in Two-Hole Blasting

Using dynamic caustics blast loading system, the paper studied the dynamic behavior of perforated crack propagation on the condition of different grooving with two borehole blasting and simultaneous initiation. Two kinds of grooving modes were designed: (a) and (b). (a): A-hole double grooving, B-hole single grooving. (b): A-hole double grooving, B-hole no grooving. As can be seen from the result, stress intensity factor decreased rapidly from the maximum, oscillated, and up to the second peak, then decreased until crack arrested. KI was almost greater than KII. The velocity and acceleration showed a type of fluctuation changes as wave. Acceleration firstly came to the peak, then the velocity came to the peak again, and the process repeated many times. The energy release rate decreased rapidly, oscillated, and then decreased. It remained the same with the variation of the stress intensity factor. Dynamic energy release rate and the dynamic stress intensity factor had the same sense of dynamic fracture mechanics.