Buckling and free vibration of exponentially graded sandwich plates resting on elastic foundations under various boundary conditions

This paper deals with the vibration and buckling behavior of exponentially graded material (EGM) sandwich plate resting on elastic foundations under various boundary conditions. New functions for midplane displacements are suggested to satisfy the different boundary conditions. The elastic foundation is modeled as Pasternak’s type which can be either isotropic or orthotropic and as a special case it converges to Winkler’s foundation if the shear layer is neglected. The present EGM sandwich plate is assumed to be made of a fully ceramic core layer sandwiched by metal/ceramic EGM coat. The governing equations of the dynamic response of non-homogeneous composite plates are deduced by using various shear deformation plate theories. Numerical results for the natural frequencies and critical buckling loads of several types of symmetric EGM sandwich plates are presented. The validity of the present solution is demonstrated by comparison with solutions available in the literature. The influences of the inhomogeneity parameter, aspect ratio, thickness ratio and the foundation parameters on the natural frequencies and critical buckling loads are investigated.