Micromechanically Based Study of Localization of Deformation and Shear BandsFormation in Brittle Materials

摘要

Understanding of the phenomenon of localization requires Construction ofmicromechanically based constitutive equations for microcracking solids, involving a number of rather complex issues of the mechanics of multiple interacting defects. Therefore, the first pan of our efforts was concentrated on several key issues of micromechanics: stress induced anisotropy and the mechanics of multiple interacting microcracks in an anisotropic environment; mechanics of secondary ('winged') microcracks forming under compressive conditions; mechanics of intersecting cracks, both in two and three dimensional configurations; the impact of compressible fluid that saturates a geomaterial on the interaction effects. The second part of our effort was focused on localization of deformation and formation of shear bands in inhomogeneous brittle materials under compression The conditions of localization and formation of shear bands are very sensitive to the exact structure of constitutive equations, in particular, to the factors like violation of the normality rule, formation of a vertex on a loading surface, dilatancy and stress induced anisotropy. These issues have been examined.