SELF-SIMILAR MODELS AND SIZE EFFECT OF MULTIPLE FRACTURE

Abstract

Multiple fracture of polyphase quasi-brittle materials is analyzed from the standpoint of similarity methods. First, two self-similar models of development of a cloud of micro- and mesocracks in an unbounded solid are constructed. Both presented models supposed that the main part of the process zone is wedge-shaped and the process zone is bounded by an arc of a circle with the center at the main crack tip. The former model is based on the hypothesis of discontinuous self-similar character of the main crack propagation, while the latter model employs physical fractal approach. Finally, the problem of size effect for bounded models is studied. It is assumed that the main cause of the size effect is that the process zone cannot be fully developed in a bounded model of a real size construction.