Numerical simulation of stress wave induced fractures in rock

Blast-induced fracture networks largely control the degree of rock fragmentation and final outcome of blasting operations. Precise laboratory-scale single-hole blast experiments have been carried out in cylindrical samples of a well-characterized granitic rock to study stress wave induced fracture patterns. The rock samples measured 144 mm in diameter and 150 mm in length. Detonating cord was employed as the explosive source in the centrally loaded boreholes in the rock samples. In this paper, the measured mechanical properties, experienced peak pressure values inside the rock samples and blast-induced fracture patterns are used to find the parameters of Johnson-Holmquist model in ANSYS AUTODYN. The resulting numerical fracture patterns are comparable to those obtained from experiments at macro-scale level.

► Results of laboratory-scale single-hole blast experiments are presented. ► By eliminating explosion gas penetration, only shock-induced cracks are considered. ► Johnson-Holmquist model in AUTODYN is calibrated for pressures and dynamic fractures. ► Model calibration is explained systematically for Barre granite. ► Resulting numerical fracture patterns are comparable to those from experiments.