19th Asia-Pacific Vibration Conference (APVC2021)

In this paper, firstly, the effective medium theory for the complex acoustic metamaterial structure is systematically developed, and the solution methods of the main effective parameters are deduced. Then, a universal applicable synergetic coupling metamaterial design method is proposed and a variety of lightweight thin-walled acoustic metamaterial structures are designed using this method to achieve low-frequency broadband strong isolation, low-frequency broadband strong sound absorption, broadband acoustic stealth, low-frequency broadband sub-diffraction and sub-wavelength acoustic focusing, low-frequency broadband multi-polarized elastic wave manipulation and ultra-light low-frequency vibration absorption. In addition to expanding the acoustic metamaterial structure system from a macro system to a macro-micro multi-scale system, it also systematically expanded the membrane-type acoustic metamaterial structure system to a plate-type and shell-type metamaterial system. Moreover, the low-frequency broadband strong sound insulation technology is realized by lightweight thin-wall acoustic metamaterial structures, and extended to large-scale applications. Finally, the low-frequency vibration absorption technology with the lightest additional weight is invented, and it is extended to the low-frequency vibration reduction application of airplanes.

Effective medium theory,Acoustic metamaterial,Synergetic coupling,Low-frequency noise and vibration attenuation,Sound focusing