Analysis of TPS Sandwich Panel with Foam Core

The method of Fourier analysis is combined with the Galerkin Method for solving the two-dimensional elasticity equations for a sandwich thermal protection system (TPS) insulation panel with foam core subjected to transverse loads. The variation of the Young’s modulus through the thickness is given by a polynomial in the thickness coordinate and the Poisson’s ratio is assumed to be constant. The Fourier series method is used to reduce the partial differential equations to a pair of ordinary differential equations, which are solved using the Galerkin method. The method will be useful is analyzing functionally graded TPS structures with arbitrary variation of thermo-mechanical properties in the thickness direction. The analysis was also performed by using one-dimensional laminated plate theory. Significant differences were found in the results suggesting that the laminate theory may not be suitable for the analysis of thick TPS.