Behaviors of cylindrical rock specimen under dynamic load

Behaviors of cylindrical rock specimen under dynamic load have been investigated by proposed test. The Hopkinson's effect at free end of specimen has been employed in this dynamic test. The PMMA pipe filled with water is arranged between the explosive and cylindrical rock specimen, and the length of the pipe is varied to adjust the strength of dynamic loading. A series of the dynamic test were carried out for Kimachi sandstone. The propagation processes of the tensile stress in the specimen were reproduced by the velocity profiles. From the distributions of the tensile stress near the free end, the relationships of the region or position of fracture surface and the stress distribution have been clearly understood.