Dynamic Response Behavior Of Thermal Protection Structure In Thermal Environment

Hypersonic flight vehicle with speed over Mach 5 is a series of flight vehicles which have high performance of maneuverability and precision strike capability. Based on the above advantages, development of hypersonic flight vehicle is highly concerned by overwhelming majority of nations.The thermal protection system(TPS) of hypersonic flight vehicle is usually imposed to terrible environment. For instance, it is subjected to severe acoustic loads reaching up to 170 dB and a thermal loading reaching up to 1200℃ in some areas. The thermal-acoustic fatigue of damage of TPS’s top face-sheet is a subject area of material and mechanics science, which is also an urgent and challenging investigation. The stochastic dynamic snap-through response of thermally buckled C/SiC ceramic composite panels under the combination of a severe acoustic excitation and a steady thermal loading. When a buckled thin-walled panel with immoveable response is excited by a severe acoustic loading, it can result in stochastic nonlinear dynamic response. It’s a post-buckling phenomenon and causes large amplitude motion between two equilibrium configurations.FPK method is used to predict the transition from no snap-through to a persistent stochastic snap-through by deriving a new parameter from single-mode Duffing equation of thin-walled structure. Result from the single-mode analysis have been validated extensively by the explicit finite element numerical simulation of the dynamic response. Accordingly, previous investigation is extend to the case of stochastic snap-through dynamic response of the thin-walled composite plate resting on an elastic foundation. The governing equation has been derived through Airy stress function and Galerkin method, which demonstrate the role of acoustic excitation level, thermal effect and elastic foundation in the dynamic response. The result shows that the elastic foundation stiffness can promote the stochastic snap-through dynamic response significantly. However, higher elastic foundation stiffness leads to smaller post-buckling deformation.