Stress state of two-layer composite elements of curved shape

Abstract

Two-layer composite structures consisting of a metal base and a polymer coating are widely used in mechanical engineering. To assess the bearing capacity and durability of such structures, methods for calculating their stress-strain state are necessary. The paper theoretically investigates the stress state of a two-layer structural element of a curved profile for two variants - under pure bending and under temperature change. The radial and meridional stresses arising in the polymer coating and the metal base of the element are taken as the studied factors. The geometric, strength, and physical characteristics of the structural element are accepted as the independent factors. Mathematical models are obtained using the plane section hypothesis. The authors investigated how the radial and meridional stresses acting in the polymer coating are related to the ratio of the coating and the metal thicknesses, as well as the metal thickness to the curvature radius. It has been established that the curvature of the metal element and the ratio of the layers thickness have the most significant effect on the magnitude of the radial stresses, and the ratio of the thicknesses on the meridional stresses. The stress state of the polymer coating is mainly determined by the ratio of the metal thickness to the radius of curvature of the boundary layer.