NONLINEAR DEFORMATION AND STABILITY OF A COMPOSITE CYLINDRICAL SHELL UNDER COMBINED LOADING BY TORQUE, BENDING MOMENT, AND INTERNAL PRESSURE.

A problem of stability of cylindrical shells made of a composite material is solved, taking into account the momentum and nonlinearity of their subcritical stress–strain state. In geometric terms, the nonlinear stability problem is solved by finite element methods and the Newton–Kantorovich linearization. Critical loads are determined in the process of solving a nonlinear problem using the Sylvester criterion. The study is carried out using the finite elements of composite cylindrical shells of natural curvature developed on the basis of the Timoshenko hypothesis, with rigid displacements being explicitly distinguished within their displacement approximation, which significantly affects the convergence of the solution. The stability of a circular cylindrical shell made of a polymer composite material under combined loading by torque, bending moment, and internal pressure is investigated. This study also touches upon the influence of the stacking method of monolayers, deformation nonlinearity, and internal pressure on critical loads at which shell buckling is observed. [ABSTRACT FROM AUTHOR]