Theoretical Modeling and Analysis of Vibroacoustic Characteristics of an Acoustic Metamaterial Plate

Locally resonant metamaterial plates with subwavelength bandgaps can be exploited for the simultaneous control of structural vibrations and acoustic radiation. The present work theoretically investigates the vibroacoustic characteristics of a metamaterial plate with periodic lateral local resonance. The high accuracy of the presented method is evident from the consistency of the cross mobility of the metamaterial plate calculated with the finite element technique. The modal superposition approach and Rayleigh integral technique are adopted to formulate the mean square velocity and acoustic radiation power in terms of the structural deflection and sound pressure to capture the vibroacoustic coupling characteristics of the metamaterial plate and the surrounding environment. Large vibration suppression and sound reduction with high radiation efficiency can be observed within the frequency ranges of interest. The near-field sound intensity and far-field acoustic pressure distributions inside and outside the bandgaps are plotted and analyzed. The results from this work can be utilized to set design guidelines for metamaterial design to achieve prescribed vibroacoustic characteristics.