Sound transmission loss overlay mechanism of plate-type acoustic metamaterials with Helmholtz resonators

Abstract

Introducing the acoustic resonator can generate an attenuation peak without degradation of the sound insulation. To reveal the mechanism of the sound transmission loss overlay, a plate-type acoustic metamaterial with Helmholtz resonators as attached masses is presented. The underlying physics is analyzed from the perspective of effective mass derived by a semi-analytical method. It is attributed to the multiplicative relationship of the effective mass. By tuning the Helmholtz resonance frequency to the vicinity of the resonance, numerical and experimental results show that an additional peak can appear at the transmission loss dip generated by the attached mass.