Buckling of simply supported FGM plates under uniaxial load

Buckling behaviour of simply supported functionally graded material (FGM) plates under constant and linearly varying in-plane compressive loads is investigated. The effect of shear deformation is studied using higher order shear deformation theories (TSDT and FSDT) for the case of uniform compression loading. For linearly varying load only the classical plate theory (CPT) is employed. The Poisson's ratio of the FGM plate is assumed to be constant, but the Young's modulus varies continuously throughout the thickness direction according to the volume fraction of constituents defined by the power-law, the sigmoid, or the exponential function. It is observed that the behaviour of FGM plates is quite similar to that of the corresponding isotopic plate. The ratio of the buckling load of FGM plates to that of isotropic plates is found to be more or less is independent of the loading parameter, the aspect ratio and the width thickness ratio of the plate and is a function of only the material gradient index. Relationships are developed to calculate the ratio of buckling loads for aluminium-alumina FGM plates.