Stability and Strength of Composite Skew Plates Under Thermomechanical Loads

The buckling and postbuckling analysis of shear deformable composite skew plates subjected to combined uniaxial compression and uniform temperature rise has been carried out using the finite element method. The governing nonlinear finite element equation is posed as a sequence of linear eigenvalue problems, and each one of them is solved for different amplitudes of deflection to trace the thermal postbuckling path. A maximum strength criterion is used to identify the laminates that have failed in strength, and appropriate modifications are made to the stiffness matrix. The first-ply failure of laminates has also been predicted by Tsai-Hill and Tsai-Wu criteria. Postbuckling paths are traced for different boundary conditions of the plate. Specific numerical studies have been reported showing the effects of skew angle, initial uniaxial compression, and thickness-to-span ratio on the thermal postbuckling behavior of the eight-layered [45/-45/0/90 deg]s symmetric plate. The presence of secondary instability has been identified while tracing the postbuckling path.