Finite Element Thermal Stress Analysis of Composite Laminates Using a Higher-Order Theory

A simple C0 isoparametric finite element formulation based on a higher-order displacement model for the analysis of symmetric and unsymmetric, composite, and sandwich laminates subjected to a thermal gradient across the thickness is presented. The displacement model accounts for the nonlinear distribution of in-plane displacement components through the plate thickness, and the theory requires no shear correction coefficients. The nine-noded quadratic Lagrangian two-dimensional element is used with five and nine degrees of freedom per node. The accuracy of the formulation is verified by analyzing sample problems available in literature. Numerical results are presented in nondimensional form for symmetric, antisymmetric, and cross-ply laminates, both thick and thin.