Hygro-thermo-mechanical stability analysis of variable thickness functionally graded sandwich porous plates resting on variable elastic foundations using finite element method

Abstract

In this study, finite element formulation of various four-unknown shear deformation theories is presented for hygro-thermal-mechanical stability analysis of variable thickness functionally graded sandwich porous (FGSP) plates resting on variable elastic foundations. In engineering practice in general and the military sector in particular, smart structures are employed relatively regularly. Three novel porosity distribution principles, which include a fully ceramic core layer and two functionally graded material surface principles, may be widely applied in those fields. These include a fully ceramic core layer and two functionally graded material surface principles, where the plate thickness changes in two directions according to bi-linear, bi-parabolic, and bi-sinusoidal laws. A quadrilateral with four nodes, each with sixteen degrees of freedom, is developed using a C1 -order conforming Hermite function and the numerical integration technique is employed in the study of hygro-thermal-mechanical stability under any boundary conditions. The results of the proposed theory and model are compared with the results available in the literature to determine the reliability of the calculation program. A collection of factors affecting the mechanical behavior of variable thickness plates with hygro-thermal-mechanical stability is described. The numerical results reveal that the porosity distribution, the thermo-humidity environment, and the variable thickness elastic foundation all impact the hygro-thermal-mechanical stability responses of FGSP plates with variable thickness.