Prediction of Vibroacoustic Response in Aircraft Cabin Under Overload

The study conducts research on the prediction of dynamic environment for high maneuverability and overload of aircraft. A numerical model of the aircraft is established and the six-degree-of-freedom motion equations combined with the improved-delayed-detached-eddy simulation (IDDES) method are used to simulate the maneuvering process of the aircraft and calculate the surface acoustic load. The calculated acoustic load is used as an external excitation for the vibroacoustic response of the cabin. Considering the impact of high static stress caused by overload on structural vibration characteristics, the low-frequency modal and high-frequency equivalent stiffness of the aircraft under overload conditions are calculated separately. The low-frequency and high-frequency responses are calculated by combining the finite element/boundary element and statistical energy analysis methods, and the full-band vibration spectrum and noise spectrum in the cabin are obtained. The calculation results indicate that the vibroacoustic response characteristics are mainly determined by external load, and the structural vibration response is dominated by low-order vibration. The main component of the noise response also comes from the low-order modal vibration of the structure. Overload has a greater impact on the low-frequency vibroacoustic response of the cabin, and as the frequency increases, the impact of overload on the vibroacoustic response gradually decreases.