Physical fracture mesomechanics of solids treated as nonlinear hierarchically organized systems

We show that one-level criteria for crack propagation in fracture mechanics should be supplemented by taking into account structure transformations in the local curvature regions of the crystal lattice in front of the crack tip. We develop a modified method of excitable cellular automata that takes into account the local torques in the crystal lattice with broken translational invariance and permits calculating the work of rotational deformation modes in crack propagation. Experimental data confirming the multilevel criteria of fracture mesomechanics are presented.