Transient Hygrothermal Analysis of FG Sandwich Plates Lying on a visco-Pasternak Foundation via a Simple and Accurate Plate Theory

Abstract

Based on a new four-unknown shear deformation theory, the hygrothermal bending response of functionally graded (FG) sandwich plates lying on visco-Pasternak foundation is investigated in this work. The present sandwich plate is composed of a homogeneous ceramic core covered by two FG layers. The properties of face layers are graded according to a power law distribution in terms of volume fraction. The governing equations are derived from Hamilton principle containing the hygrothermal effects employing the suggested theory. This theory includes only four unknown functions and accounts for quasi-parabolic distribution of transverse shear stress. In addition, it satisfies the free traction conditions at the top and bottom surfaces of the plate. By varying the thickness of the core, several types of FGM sandwich plates are obtained and studied. By comparing the present results with those available in the literature, the present theory is validated. Parametric studies are executed to demonstrate the effects of humidity, temperature rise, foundation coefficients, core thickness, and power law index on the bending of FGM sandwich plates.