An analytical study of sound transmission through corrugated core sandwich plates

The unique core structure makes the corrugated sandwich plate with enhanced strength and stiffness while maintaining a relatively lighter mass, with simple structure and low manufacturing cost, which has a significant potential for widespread applications. To better evaluate its acoustic performance, a theoretical model for vibration analysis under simply supported boundary conditions is established using the first-order shear deformation theory (FSDT) and Hamilton's principle, as well as formulates the sound insulation equation for the sandwich panel subjected to simple harmonic pressure excitation. The solution is further solved analytically based on the fluid-structure coupling condition and the Navier method, and the sound transmission loss (STL) is described analytically. The validity of the proposed model is verified by comparing with the results of impedance tube acoustic insulation experiment and commercial software COMSOL finite element simulation. Based on the approach presented in this article, the effects of sandwich layer thickness, corrugation angle, sandwich plate size and corrugation wall thickness on the acoustic and vibration characteristics of the structure are discussed. The findings demonstrate that, the natural frequency of the sandwich panel undergoes a decrease as the corrugated inclination increases. Specifically, when the corrugated inclination angle rises from 30 degrees to 70 degrees, the overall sound insulation effect improves by 8.73 %. An increase in the core thickness results in a decrease in the resonance frequency of the sandwich plate, and the sandwich plate exhibits good sound insulation across a wide frequency band when the core thickness reaches 12 mm. As the thickness of the corrugated wall increases, a trend towards lower frequencies of the sound insulation trough is observed, and when the corrugated wall thickness increases from 1 mm to 3 mm, the average STL of sandwich panel enhanced by 12.57 % in the whole frequency analysis.