Dynamic Fracture Analysis Based on a Continuum Damage Model

Because of its potential utilization in energy exploration and defense applications, the phenomenon of brittle fracture in solids under dynamic loads has been an ongoing topic of interest. A continuum damage model [1] was developed to simulate rock fragmentation induced by explosive blasts for in situ oil shale retorting. The model was based on the premise that the inelastic brittle response exhibited by rock under dynamic loads is due principally to the stress-induced sub-scale cracks. Locally, the growth and interaction of these sub-scale cracks relieve portions of the material volume and reduce its capability to carry load. Globally, this effect is reflected in the degradation of the material stiffness. In this manner, the dynamic fracture process was modeled as a continuous accrual of damage, where damage is considered to be the degree of reduction of the material stiffness. Reasonable correlations between calculated and measured data were obtained by this model [1–3].