Nonlinear thermo-mechanical stability of multilayer-FG plates reinforced by orthogonal and oblique stiffeners according to FSDT

This paper presents an analytical approach to investigate the nonlinear stability of multilayer-functionally graded plates stiffened by orthogonal and/or oblique functionally graded stiffeners subjected to axial compression and/or thermal load. The equilibrium equation system is established by using the first-order shear deformation plate theory taking into account the plate–foundation interaction, geometrical nonlinearity in von Kármán sense and initial geometrical imperfection. An improved Lekhnitskii’s smeared stiffener technique is applied for oblique stiffeners with thermal terms and shear deformation of stiffeners. The governing equations are solved by Galerkin procedure to obtain the explicit expressions of buckling loads and postbuckling load–deflection curves. Results show the effects of material and geometrical properties, boundary conditions, elastic foundation parameters and initial imperfection on the buckling and postbuckling load-carrying capacity of plates.