FRACTURE THEORY FOR NONHOMOGENEOUS BRITTLE MATERIALS WITH APPLICATION TO ICE.

Brittle heterogeneous materials generally fracture with a dispersed zone of microcracking at the fracture front. The deformation and failure of these materials can be described by a nonlocal continuum theory, the special case of which is the blunt crack band model, in which a band of continuously distributed (smeared) cracks of a certain fixed width is assumed to exist at the fracture front. This model is easily implemented in finite element codes, and a dimensional analysis leads to a simple size effect law for the nominal stress at failure of geometrically similar specimens. The current state of this theory, which has been shown to apply to concrete and rocks, is briefly outlined and the possibility of application to ice is discussed. Comparison with a large series of test data by Butiagin suggests that nonlinear fracture mechanics based on the crack band model may indeed be applicable to ice.