Нелинейное деформирование и устойчивость композитной цилиндрической оболочки при комбинированном нагружении изгибающим моментом и краевой поперечной силой

Abstract

Currently, polymer composite materials are widely used in the modern aircraft structures. Their application significantly reduces the weight of the structure, while maintaining its strength and stiffness characteristics. A large number of works have been published on the study of the strength of such structures, but the issues of strength and stability during their nonlinear deformation remain unresolved. There is a small number of works on the study of strength and stability of thin-walled shells made of polymer composite materials. The latter is especially necessary for thin-walled aircraft fuselage structures, where the loss of composite skin stability is unacceptable. The problem of determining the influence of the stacking order of monolayers in a skin on the strength and stability of composite material shells under nonlinear deformation remains unsolved. Methods for calculating the strength and stability of thin-walled composite structures, regarding the nonlinearity of the initial stress-strain state, are not well developed. Therefore, the development of reliable and efficient methods for calculating shells made of composite materials is an urgent task. The article describes solving the problem of strength and stability of cylindrical composite shells under arbitrary loading using finite element methods and Newton-Kantorovich linearization. Critical loads have been determined in the course of solving a geometrically nonlinear problem using the Sylvester criterion. The stability of a circular cylindrical shell made of a polymer composite material has been studied under combined loading by a bending moment and a transverse force. The influence of the nonlinearity of deformation, methods of stacking monolayers on the shell critical loads has been determined.