MULTIFRACTAL FRACTURE-TOUGHNESS PROPERTIES OF BRITTLE HETEROGENEOUS MATERIALS

This paper documents a study of novel fracture-toughness properties of brittle heterogeneous materials. Through simulations of the rupture p rocess based on a lattice discretization of the material, the spatial variation of dissipated energy due to fracture is evaluated. Under cer tain conditions, its distribution is characterized by a multifractal s pectrum f(alpha). Importantly, f(alpha) depends not only on the initia l heterogeneity present in the material but also on the nature of the externally applied load. This provides a renewed load-path-dependent d efinition of fracture roughness material properties. It avoids the dif ficulties associated with 'traditional' continuum/fracture mechanics d efinitions where the macroscopic fracture mode must be known a priori.