Performance of a higher-order triangular finite element for composite laminated structures

In general, the shear stiffness of composite materials is much lower than that of conventional engineering materials and the transverse shear deformation is not negligible in analyzing composite structures. Unfortunately, many finite elements which include transverse deformation become too stiff when dealing with thin composite laminated plates. Therefore, a new higher-order triangular finite element model with six nodes, which includes transverse shear effects and can deal with both very thin and thick composite laminated structures, is developed in this dissertation. The basic element tests for isotropic and orthotropic materials are conducted and the results are compared with the theoretical solutions. Also, several typical bending problems for composite laminated structures, such as cross-ply, angle-ply, sandwich and swept plates and cantilever laminated beams with different stack sequences, are solved using the present finite element model, and the results are compared with their corresponding exact solutions wherever possible or those of some other existing finite element models. Interlaminar shear stress calculation and comparisons for isotropic and anisotropic plates are also presented