Postbuckling of pressure-loaded FGM doubly curved panels resting on elastic foundations in thermal environments

• The initial deflection caused by lateral pressure is taken into account.
• The initial deflection caused by thermal bending stresses is taken into account.
• Heat conduction is taken into account.
• Temperature-dependent material properties are taken into account.
• Material properties of FGMs are based on Mori–Tanaka micromechanics model.

Modeling and analysis for the postbuckling of FGM doubly curved panels resting on elastic foundations and subjected to lateral pressure under heat conduction are presented. The initial deflections caused by lateral pressure and thermal bending stresses are both taken into account. The temperature-dependent material properties of functionally graded materials (FGMs) are assumed to be graded in the thickness direction based on Mori–Tanaka micromechanics model. The formulations are based on a higher order shear deformation theory with von Kármán strain–displacement relationships. The panel-foundation interaction and thermal effects are also included. The governing equations are first deduced to a boundary layer type that includes nonlinear prebuckling deformations and initial geometric imperfections of the panel. These equations are then solved by means of a singular perturbation technique along with a two-step perturbation approach. The effects of volume fraction index, temperature variation, the panel geometric parameters as well as foundation stiffness on the postbuckling behavior of FGM doubly curved panels are discussed in detail.