Vibro-acoustic behaviors of a plate-cavity symmetrically embedded with suppressed acoustic spots

Abstract

Control of structural vibration and noise is crucial in the engineering field, and research on related technologies has significant engineering applications. This paper presents a semi-analytical analysis method to evaluate the vibro-acoustic properties of plate-cavity coupled systems with single or multiple symmetrically embedded suppressed acoustic spots (SAS). The numerical element division method (NEDM) combined with a power-law function to discretely approximate the SAS domain is used to solve the complex boundary integration problem. The spectral-geometry method (SGM) is adopted to express the plate displacement and the sound pressure in the cavity as continuous modified Fourier series to ensure boundary smoothness. Based on the Lagrange energy principle, the coupled theoretical model is constructed and the modal parameters are solved by the generalized Rayleigh-Ritz method, the accuracy of which is verified by comparison with the finite element method (FEM). The study discusses the vibro-acoustic attenuation mechanism of the SAS plate-cavity coupled system under the sound source excitation in the cavity, and the SAS plate parameters are analyzed in depth. The results reveal that when SAS with damping layers (SAS+DL) plates are used for noise reduction, an optimal match between SAS and damping layers needs to be sought rather than simply increasing SAS or damping, which provides a potential theoretical research basis for the design of damped structures applying the SAS principle.