Postbuckling analysis of shear-deformable composite laminated plates on two-parameter elastic foundations

Postbuckling analysis is presented for a simply supported, shear-deformable , composite laminated Flare subjected to uniaxial compression and resting o n a two-parameter (Pasternak-type) elastic foundation. The initial geometri c imperfection of the plate is taken into account. Two cases of in-plane bo undary conditions are considered. The formulations are based on Reddy's hig her-order shear-deformation plate theory, including plate-foundation intera ction. The analysis uses a deflection-type perturbation technique to determ ine buckling loads and postbuckling equilibrium paths. Numerical examples a re presented that relate to the performance of perfect and imperfect, antis ymmetric angle-ply and symmetric cross-ply laminated plates resting on Past ernak-type elastic foundations from which results for Winkler elastic found ations are obtained as a limiting case. The effects played by foundation st iffness, transverse shear deformation, the character of the in-plane bounda ry conditions, plate aspect ratio, total number of plies, fiber orientation , and initial geometric imperfections are studied.