Galishin A. Axisymmetric geometrically nonlinear thermoviscoelastoplastic state of compound shells with damage of material taken into account

The scientific and technical problem consisting in development of the technique for determination of axisymmetric thermoviscoelastoplastic geometrically nonlinear deformation of compound shells with accounting of material damage is solved. The shells are composed of isotropic and orthotropic layers and are subjected to the loads that cause the meridional stress state and torsion. The equations of the theory of proportional loading as well as the relations of the deformation processes along the trajectories of a small curvature for isotropic layers are used. For orthotropic layers the Hook's law is applied. To investigate the material damage under thermoviscoelastoplastic deformation the Rabotnov's equation is utilized. The equivalent stress is defined accounting of a kind of stress state. The technique for determination of a creep and long-duration strength parameters for unisothermal loading processes, and also the technique for determination of tangential stresses that is based on a numerical integration of the equilibrium equations for stresses, are developed. New problems of axisymmetric geometrically nonlinear thermoviscoelastoplastic deformation of compound shells are solved and the new effects of their failure are established.