Impact of Fluid-Thermal-Structural Coupling on Response Prediction of Hypersonic Skin Panels

The goal of the United States Air Force to field durable platforms capable of sustained hypersonic flight and responsive access to space depends on the ability to predict the response and the life of structures under combined aerothermal and aeropressure loading. However, current predictive capabilities are limited for these conditions due in part to the inability to seamlessly address fluid-thermal-structural interactions. This study aims to quantify the significance of a frequently neglected interaction, namely: the mutual coupling of structural deformation and aerodynamic heating, on response prediction. The quasi-static response of a carbon carbon skin panel is investigated. It is found that the significance of this coupling depends largely on the in-plane boundary conditions, since increasing resistance to thermal expansion results in buckling and increasing deflections into the flow. Including these deformations in aerodynamic heating results in O(10%) increase in peak temperature and O(100%) increase in surface ply failure index for deflections O(1%) of panel length. In these cases, the locations of peak temperatures and stresses are significantly altered. Finally, neglecting deformations in the aeroheating analysis results in the prediction of snap-through for a gradual heating trajectory, whereas, inclusion leads to a higher mode dominated, dynamically stable response.