Gavrilov G. The linear problems of fracture mechanics of aging viscoelastic anisotropic materials under constant external loading.

The Thesis is devoted to the new problems of long-term fracture of aging viscoelastic and anisotropic materials under stationary loading. The solutions of long-term fracture of aging orthotropic materials with macrocracks is obtained for cases of plane strains and plane stresses. And the solution of long-term fracture of aging transversally-isotropic material with internal penny-shaped macrocrack is also obtained. Fiber composite materials which are modelled by homogeneous anisotropic media with effective mechanical properties is considered as the anisotropic materials. Modified model of crack with constant length of failure zone and critical opening displacement in the crack tip criterion are considered. The solutions are built on the basis of Volterra principle and the operator continued fractions method. Numerical calculations of the nonlinear integral equations of crack growth and study of long-term fracture behavior are performed for specific aging composite materials.