Vibration Response Characteristics of Acoustic Liner Structure Under High-Intensity Acoustic Excitation

Acoustic liners are widely employed in aero-turbofan engines for noise suppression. During actual operation, such structures are subjected to complex thermal and acoustic loads, resulting in intense vibration responses and posing a threat to structural integrity. A thermo-acoustic-structural-coupled numerical model was established based on the coupled finite element/boundary element (FEM/BEM) method. To validate the accuracy of this numerical method, thermo-acoustic experiments were conducted on thin-walled metal plates within a high-temperature traveling wave tube; the maximum errors for thermal modal frequency and strain were maintained within 7.4% and 13.3%, respectively. Based on actual aero-engine boundary conditions, steady-state thermal loads and high-intensity acoustic excitation were applied to the acoustic liner structure to calculate the dynamic response under different loading conditions. The results indicate that temperature primarily governs the surface stress distribution of the acoustic liner, causing a shift in the location of structural danger points. The stress magnitude is predominantly influenced by the sound pressure level (SPL), exhibiting a positive correlation. Under traveling wave loading, an increase in the incident angle significantly amplifies the stress and strain response amplitudes and shifts the peak frequency of the stress power spectral density (PSD) toward higher frequencies. This study provides a theoretical reference for the dynamic response-based design optimization of acoustic liner structures and a basis for subsequent thermo-acoustic fatigue assessment under complex loading conditions.