Functionally graded materials (FGM) are a class of composites, in which the properties of the material gradually change over one or more Cartesian directions, the combination of which results in an assembly with higher performance than components taken separately. This class of composite materials has gained considerable attention in the engineering community, especially in high-temperature applications such as nuclear reactors, aerospace, and power generation industries. The aim of the current work is to study the influence of homogenization (idealization) models and thermal loads on static deflection behavior of sandwich functionally graded plate. Several micromechanical models have been employed to obtain the effective material properties of the two-phase FGM plate. The FGM plate is subjected to linear and no linear thermal loads. The integral theory used contains only four variable functions as against five in the case of other HSDTs. The governing equation are derived and resolved via virtual work principle and Navier's model. The accuracy of the proposed analytical model is confirmed by comparing the results with those given by others model existing in the literature.

Functionally graded materials (FGM) are a new range of composite materials having a gradual and continuous variation of the volume fractions of each of the constituents (in general, metal and ceramic) in thickness, which accordingly causes changes in the overall thermomechanical properties of the structural elements they constitute. The interest of this work is the use of a high-order plate theory for the study of thermal buckling of FGM plates resting on Winkler-Pasternak type elastic foundation. The present method leads to a system of differential equations, where the number of unknowns is five. The material properties of FGM plate such as Young's modulus and coefficient of thermal expansion are assumed to be variable through the thickness according to the Mori-Tanaka distribution model. The thermal loading is assumed to be uniform, linear and nonlinear through the thickness of the plate. A parametric study is thus developed to see the influence of the geometric and mechanical characteristics, in particular, the geometric ratio (a/b), thickness ratio (a/h) and the material index (k), as well as the impact of the Winkler and Pasternak parameters on the critical buckling load.