ИСТИНА

Existing experimental data demonstrate a strong stress-state sensitivity of the deformation properties of a wide class of solids, including metals (steels, aluminium, copper, cast iron), rocks (sandstone, marble, limestone, talc chloride), structural graphites, and some other materials. Investigation of the asymptotic behaviour of the stress, strain, and displacements in the vicinity of a mixed-mode crack in the stress-state sensitive materials leads one to conclude that the traditional approaches, such as the superposition of the solutions as well as the assumptions for the symmetrical or antisymmetrical stress distributions are not always be applicable for the materials with the physically nonlinear stress-strain relations. Nevertheless, a nontrivial solution with in the displacement series is found explicitly that demonstrates such specific features as the volume change under the condition of the remote shear loading as a consequence of inherent interrelation between shear and volume deformation processes in the given materials. In addition, it is seen that the stronger the material stress-state-sensitivity is the stronger the resulting stress, strain, and displacement fields deviate from the linear elastic ones.