3D-degenerated thermal shell element analysis in composite laminates

According to the geometric form of a shell element, geometric formulations of the shell element are deduced. This paper supposes that temperature has quadratic variation through layers of the shell element, and gives the expression of temperature functions in given boundary conditions. In this paper, the orthotropic feature of material property is considered; heat conductivity can be transformed from material coordinates into element coordinates and then the formulations of thermal analysis are deduced. Finite element formulations are established using 3D-de-generated shell element and then thermal shell formulations are gotten. Thus this method can change 3D problems into 2D problems. Then a program is designed to test this theory. It not only has the same precision with isoparametric element, but also improves the efficiency of analysis. It also can save memory of computer and running time. The numerical results are compared with ANSYS results and are satisfactory.