Two-Dimensional Orthotropic Plate Analysis for an Integral Thermal Protection System

This paper is concerned with homogenization of a corrugated-core sandwich panel, which is a candidate structure for integrated thermal protection systems for space vehicles. The focus is on determining the local stresses in an integrated thermal protection system panel subjected to mechanical and thermal loads. A micromechanical method is developed to homogenize the sandwich panel as an equivalent orthotropic plate. Mechanical and thermal loads are applied to the equivalent thick plate, and the resulting plate deformations were obtained through a shear deformable plate theory. The two-dimensional plate deformations are used to obtain local integrated thermal protection system stresses through reverse homogenization. In addition, simple beam models are used to obtain local facesheet deformations and stress. The local stresses and deflections computed using the analytical method were compared with those from a detailed finite element analysis of the integrated thermal protection system. For the integrated thermal protection system examples considered in this paper, the maximum error in stresses and deflections is less than 5%. This was true for both mechanical and thermal loads acting on the integrated thermal protection system.