Vibro-acoustic coupling characteristics of the microperforated panel with local resonators

This paper provides a unified approach to evaluate the sound absorption performance of the metamaterial microperforated panel (MMPP) with additional local resonators under elastic boundaries. The elastic boundary conditions can be realized by setting the stiffness of restrained spring at the edges as a specific value. The vi-bration equations of the metamaterial panel (MP) are derived by combining the Spectral Geometry method with the Rayleigh Ritz method, and the acoustic electrical analogy method is used to solve the absorption coefficient considering the vibro-acoustic coupling. The program developed by these methods can be used to study the vibro-acoustic coupling model of the MMPP with various parameters under various boundaries. To validate the accuracy of the present method, a structure-acoustic simulation model is established, and a good agreement is achieved between the theoretical method and the finite element method. A comprehensive parametric analysis is performed to obtain the optimum suppression performance of sound absorption and the variation of the ab-sorption coefficients has been explained justifiably in detail. The results demonstrate that additional local res-onators can improve the absorption performance of the microperforated panel, and the absorption band can be appropriately broadened by reducing the spring stiffness or increasing mass ratio. This paper provides a better sound absorption prediction for the practical application of MMPP under complex conditions.