Mechanisms of structural thermal stress influence on hypersonic aerothermoelasticity

Aerothermoelasticity is essential for the study of hypersonic vehicles, as structural thermal stress significantly influences aerothermoelastic behavior. This paper develops an analysis framework for aerothermoelasticity based on a layered solution approach, focusing on the mechanisms by which structural thermal stress affects aerothermoelastic characteristics under both uniform and non-uniform temperature conditions. Departing from conventional aerodynamic heating approaches, direct structural temperature control is employed to isolate thermal stress effects. Through analyzing thermal stress distribution, natural modes, and dynamic system coupling instability, the mechanisms underlying thermal stress effects are elucidated. Results reveal that thermal stress induces non-monotonic changes in natural frequency, modal characteristics, and flutter behavior, closely linked to thermal buckling under high-temperature conditions. While similar thermal stress effects are observed under uniform and non-uniform temperature conditions, the latter exhibits distinct behaviors, including a more pronounced reduction in natural frequency and flutter boundary prior to buckling, as well as potential static divergence near critical temperatures. This study enhances the understanding of thermal stress impacts on aerothermoelasticity and provides practical insights for the thermal structural design of hypersonic vehicles.