Thermal postbuckling of preloaded shear deformable laminated plates

Postbuckling analysis is presented for a simply supported, shear deformable laminated plate subjected to a uniform lateral pressure and thermal loadin g, and resting on an elastic foundation. The temperature fields considered are associated with a nonuniform tentlike and parabolic distribution over t he plate surface. The material properties are assumed to be independent of temperature. The lateral pressure is first converted into an initial deflec tion, and the initial geometric imperfection of the plate also is taken int o account. The formulations are based on Reddy's higher-order shear deforma tion plate theory and include the plate-foundation interaction and thermal effects. The analysis uses a mixed Galerkin-perturbation technique to deter mine the thermal postbuckling equilibrium paths. The numerical illustration s concern the thermal postbuckling behavior of preloaded antisymmetric angl e-ply laminated plates under a tentlike temperature field and symmetric cro ss-ply laminated plates under a parabolic temperature field resting on Past ernak-type or softening nonlinear elastic foundations from which the result s for Winkler elastic foundations are obtained as a limiting case. The effe cts played by foundation stiffness, fiber orientation, transverse shear def ormation, the plate aspect ratio, thermal load ratio, and initial geometric imperfection as well as initial lateral pressure are studied.