Nonlinear postbuckling of symmetric S-FGM plates resting on elastic foundations using higher order shear deformation plate theory in thermal environments

This paper presents an analytical investigation on the postbuckling behaviors of thick symmetric functionally graded plates resting on elastic foundations and subjected to thermomechanical loads in thermal environments. Material properties are graded in the thickness direction according to a Sigmoi power law distribution in terms of the volume fractions of constituents (S-FGM). The formulations are based on third order shear deformation plate theory and stress function taking into account Von Karman nonlinearity, initial geometrical imperfection, temperature and Pasternak type elastic foundation. By applying Galerkin method, closed-form relations of buckling loads and postbuckling equilibrium paths for simply supported plates are determined. The effects of material and geometrical properties, temperature, boundary conditions, foundation stiffness and imperfection on the mechanical and thermal buckling and postbuckling loading capacity of the S-FGM plates are analyzed and discussed.