ИСТИНА

Based on the formulated three-dimensional variational principles of Lagrange, Castigliano and Reissner type for the theory of multilayer thin bodies, the corresponding variational principles are derived for the theories of five-layer thin bodies at moments with respect to systems of orthogonal polynomials under various interlayer contact conditions. As special cases, classical and micropolar thin and shallow and prismatic thin bodies, as well as the bodies of revolution, are considered. In particular, cylindrical, conical and spherical thin bodies are considered. Based on the principles of Lagrange and Castigliano, finite elements are created.