Heterogeneous materials—Scaling phenomena relevant to fracture and to fracture toughness

The paper documents a study on novel fracture and fracture toughness properties of brittle heterogeneous materials. Before any external load is applied on a structure/specimen, certain material relevant variables are considered to form a random field. The implications of these underlying heterogeneous fields before fracture on the properties of the fracture network developed from external load application are examined first. Then, emphasis is given on the distribution of the spatial variation of the dissipated energy due to fracture which shows, under certain yet general conditions, multifractal scaling properties. Importantly such scaling depends not only on the initial heterogeneity present, but also on the externally applied load and on the nature and extend (depth) of relevant surface effects. From the engineering point of view, such properties of dissipated energy provide a renewed load-path as well as structure dependent definition of fracture toughness.