Shcherbii A. Limit equilibrium of cracked shallow shells with flexible coating.

The influence of the one-sided flexible coating on the stress-strain state and the limit equilibrium of cracked shallow shells are studied in the thesis. Within the framework of the classical Kirchhoff-Love theory of shells, a crack in a shell with a flexible coating is interpreted as a cut, the edges of which are hinged at the front surface of the shell. The problem of statics of shallow shell with connected boundary conditions on the cut is formulated. The asymptotic solutions for coated shells of arbitrary shape with a crack along the line of curvature and numerical solutions for a spherical shell with a meridional crack and a cylindrical shell with a longitudinal or circumferential crack are constructed by singular integral equations method. The range of applicability of the asymptotic results is determined. The interaction of collinear cracks in shells with a coating is investigated. To assess the limit equilibrium of coated cracked it is proposed to use two criteria: the energy criterion for brittle fracture of the shell and the classical criterion for the coating strength. It was found that the reinforcement of the shell from the outside is more advantageous than from the inside.