Nonlinear thermo-mechanical stability of shear deformable FGM sandwich shallow spherical shells with tangential edge constraints

Abstract

This paper presents an analytical approach to investigate the nonlinear axisymmetric response of moderately thick FGM sandwich shallow spherical shells resting on elastic foundations, exposed to thermal environments and subjected to uniform external pressure. Material properties are assumed to be temperature independent, and effective properties of FGM layer are graded in the thickness direction according to a simple power law distribution in terms of the volume fractions of the constituents. Formulations are based on first-order shear deformation shell theory taking geometrical nonlinearity, initial geometrical imperfection, Pasternak type elastic foundations and various degree of tangential constraint of boundary edge into consideration. Approximate solutions are assumed to satisfy clamped boundary condition and Galerkin method is applied to derive closed-form expressions of critical buckling loads and nonlinear load-deflection relation. Effects of geometrical parameters, thickness of face sheets, foundation stiffness, imperfection, thermal environments and degree of tangential edge constraints on the nonlinear stability of FGM sandwich shallow spherical shells are analyzed and discussed.

Free vibration of FG sandwich plates partially supported by elastic foundation using a quasi-3D finite element formulation

“…The effects of Winkler and Pasternak foundation parameters on bending of FG plates were considered by Al Khateeb and Zenkour [22], taking the influence of temperature and moisture into account. The influence of tangential edge constraints and foundation support on buckling and postbuckling behaviour of FG sandwich plates and FG sandwich spherical shells was respectively considered by Tung [23], Khoa and Tung [24] using the Galerkin method. Based on a hyperbolic shear and normal deformation plate theory, Akavci [25] carried out static bending, buckling and free vibration analyses of FG sandwich plates supported by a Pasternak foundation.…”