A stochastic energy finite element method for predicting the high-frequency dynamic response of panels under aero-thermo-acoustic loads

Skin panels on supersonic vehicles are subjected to aero-thermo-acoustic loads, resulting in a well-known multi-physics dynamic problem. The high-frequency dynamic response of these panels significantly impacts the structural safety of supersonic vehicles, but it has been rarely investigated. Given that existing methods are inefficient for high-frequency dynamic analysis in multi-physics fields, the present work addresses this challenge by proposing a Stochastic Energy Finite Element Method (SEFEM). SEFEM uses energy density instead of displacement to describe the dynamic response, thereby significantly enhancing its efficiency. In SEFEM, the effects of aerodynamic and thermal loads on the energy propagation characteristics are studied analytically and incorporated into the energy density governing equation. These effects are also considered when calculating the input power generated by the acoustic load, and two effective approaches named Frequency Response Function Method (FRFM) and Mechanical Impedance Method (MIM) are developed accordingly and integrated into SEFEM. The good accuracy, applicability, and high efficiency of the proposed SEFEM are demonstrated through numerical simulations performed on a two-dimensional panel under aero-thermo-acoustic loads. Additionally, the effects and underlying mechanisms of aero-thermo-acoustic loads on the high-frequency response are explored. This work not only presents an efficient approach for predicting high-frequency dynamic response of panels subjected to aero-thermo-acoustic loads, but also provides insights into the high-frequency dynamic characteristics in multi-physics fields.