Thermal buckling behaviour of variable stiffness laminated composite plates

Here, the thermal buckling behaviour of variable stiffness laminated composite plates subjected to thermal loads is numerically studied employing finite element approach based on first-order shear deformation theory. In the composite laminate considered here, the fibre orientation varies continuously within the layer leading to spatial variation of stiffness in the laminate. Different types of thermal loadings such as uniform and non-uniform temperature distributions are assumed in the analysis. The governing equations developed, applying the principle of minimization of total potential energy, are solved through an eigenvalue approach. The displacement field of pre-buckling of the laminate is evaluated before proceeding for the thermal buckling analysis depending on the type of temperature distributions. The formulation is tested against problems for which the solutions are available. A detailed study considering various design parameters such as curvilinear fibre angles at the centre and edge of the lamina, lay-up, thickness ratio, coefficients of thermal expansion, and modular ratio is made on the critical buckling temperature. The present analysis shows the significant change in the critical thermal buckling parameter while varying the curvilinear fibre angles and lay-up of the laminate.