TRANSIENT THERMAL CONDUCTION IN RECTANGULAR FIBER-REINFORCED COMPOSITE LAMINATES

A finite element formulation based on the Fourier law of heat conduction is presented to analyze the transient temperature distribution in rectangular fiber-reinforced composite plates. Three-dimensional twenty-noded brick elements are used to discretize the spatial domain of the plate. A Crank-Nicolson time marching scheme is used to solve the resulting time-dependent ordinary differential equations. The finite element solution is tested for convergence of results with mesh refinement. Further, the FEM is validated comparing the qualitative nature of results obtained for a plate made of aluminium and steel laminae with that of Tanigawa et al. Results are presented for graphite/epoxy and graphite-kevlar/epoxy plates subjected to different thermal boundary conditions. Laminae with fiber orientations of 0 degrees, +/-45 degrees, and 90 degrees are considered for the analysis. The results indicate that the temperature variation in the plane of the plate (x-y plane) is very much dependent on the boundary conditions. When the faces of the plate through the thickness are insulated, the number of elements in the x-y plane is observed to have no effect on the accuracy of the results.