THE MICROMECHANICS OF IMPACT FRACTURE OF ROCK

Abstract Impact methods are used to create controlled dynamic fracture in Arkansas novaculite and laser interferometry is used to determine the time resolved stress during fracture. Experimental fracture stresses and fracture energies are determined under varying dynamic tensile loading conditions. Rate-dependent fracture is observed and found to be in accordance with concepts of linear elastic fracture mechanics applied to microstructural fracture initiation. A micromechanical fracture model based on these concepts is used to calculate the dynamic fracture results.