Modeling the high temperature behavior of all-composite, corrugated-core sandwich panels undergoing ablation

Owing to their structural efficiency, the development of structurally integrated thermal protection systems (SITPS) for the next generation aerospace vehicles is currently of interest. Herein, an all-composite sandwich structure with corrugated core is devised and fabricated. After homogenization of the corrugated core, a one-dimensional (1-D) analytical model is developed. The surface ablation is described by considering thermal decomposition, phase transition and thermochemical ablation. With the thermal loading and moving boundary conditions determined by the surface ablation calculation, a heat transfer analysis is performed. To provide insight into the effect of lateral heat transfer and thermal short through the sandwich structures, a two-dimensional (2-D) finite element model is also presented. In addition, a thermal exposure experimental test with oxyacetylene flame is carried out to validate the proposed models. The 1-D analytical model is found to be of satisfactory accuracy, which is useful for rapid preliminary SITPS design.