Low-frequency vibroacoustic performance of an acoustic metamaterial plate with periodical single-stage multi-degree-of-freedom resonators attachment

Abstract

This paper demonstrates low-frequency vibration suppression and sound radiation of an acoustic metamaterial plate which is composed of periodical single-stage multi-degree-of-freedom (MDOF) resonators and a homogeneous plate. Dispersion relation for a unit cell and vibroacoustic performance for a simply supported metamaterial plate has been derived. Multiple band gaps can be obtained for the metamaterial plate, within which large vibration suppression and sound reduction can be achieved for the finite simply supported metamaterial plate. Analysis of the infinite and finite meta-plate implies a validation between these two theoretical methods. Low-frequency vibration suppression and sound reduction within band gaps can be attributed to the translational and rotational resonance from the attached resonators which generate inertia to counterbalance the shear force in the plate induced by the flexural wave. Study in this work shows potential in the practical application for requirements of small room installation and multiple band gaps.