This paper investigates the effects of tangential edge constraints and elastic foundations on the buckling and postbuckling behavior of thick FGM rectangular plates resting on elastic foundations and subjected to thermal and thermomechanical loading conditions. | Vietnam Journal of Mechanics, VAST, Vol. 38, No. 1 (2016), pp. 63 – 79 DOI: THERMOMECHANICAL POSTBUCKLING OF THICK FGM PLATES RESTING ON ELASTIC FOUNDATIONS WITH TANGENTIAL EDGE CONSTRAINTS Hoang Van Tung Hanoi Architectural University, Vietnam ∗ E-mail: inter0105@ Received September 17, 2015 Abstract. This paper investigates the effects of tangential edge constraints and elastic foundations on the buckling and postbuckling behavior of thick FGM rectangular plates resting on elastic foundations and subjected to thermal and thermomechanical loading conditions. Material properties are assumed to be temperature dependent, and graded in the thickness direction according to a simple power law distribution in terms of the volume fractions of constituents. Governing equations are based on the higher order shear deformation plate theory incorporating the von Karman geometrical nonlinearity, initial geometrical imperfection, tangential edge constraints and Pasternak type elastic foundations. Approximate solutions are assumed to satisfy simply supported boundary conditions and Galerkin procedure is applied to derive expressions of buckling loads and load-deflection relations. In thermal postbuckling analysis, an iteration algorithm is employed to determine critical buckling temperatures and postbuckling temperaturedeflection equilibrium paths. The separate and simultaneous effects of tangential edge restraints, elastic foundations and temperature dependence of material properties on the buckling and postbuckling responses of higher order shear deformable FGM plates are analyzed and discussed. Keywords: Functionally graded materials, tangential edge constraint, temperature dependent property, buckling and postbuckling, elastic foundations. 1. INTRODUCTION Functionally graded materials (FGMs) are microscopically composites usually composed from a mixture of metal and ceramic constituents and have some advanced features in comparison .