Thermomechanical postbuckling of imperfect shear deformable laminated plates on elastic foundations Original Research Article

Postbuckling analysis is presented for a simply supported, shear deformable composite laminated plate subjected to combined axial and thermal loads and resting on an elastic foundation. The two cases of thermal postbuckling of initially compressed plates and of compressive postbuckling of initially heated plates are considered. The initial geometric imperfection of the plate is taken into account. The formulations are based on Reddyʹs higher order shear deformation plate theory, including the plate-foundation interaction and thermal effects. The analysis uses a perturbation technique to determine the buckling loads and the postbuckling equilibrium paths. Numerical examples are presented that relate to the performances of perfect and imperfect, antisymmetric angle-ply and symmetric cross-ply laminated plates resting on Pasternak-type or softening nonlinear elastic foundations from which results for Winkler elastic foundations are obtained as a limiting case. The effects played by foundation stiffness, transverse shear deformation, plate aspect ratio, total number of plies, fiber orientation and initial geometric imperfections are studied.