论文期刊

Broadband low-frequency membrane-type acoustic metamaterials with multi-state anti-resonances




作者: Guojian Zhou, Jiu Hui Wu, Kuan Lu, Xiujie Tian, Wei Huang, Keda Zhu
发表/完成日期: 2019-09-24
期刊名称: Applied Acoustics
期卷: Vol.159, 2020
相关文章: Zhou Guojian_Broadband low-frequency membrane-type acoustic metamaterials with multi-state anti-resonances.pdf   
论文简介
In this paper, a well-designed low-frequency membrane-type acoustic metamaterial (MAM) with continuous multi-state anti-resonance modes is proposed, which may effectively broaden a sound attenuation
zone in low-frequency regime and produce single-negative effective parameter characteristic. Firstly,
four lightweight MAM samples with distinct resonator distributions are purposefully designed, based
on the low-order vibration characteristics of membrane and the design concept of dynamic balance.
Then, the realization principle of the multi-state anti-resonance modes and the regulation mechanism
of the sound transmission loss (STL) are progressively compared and investigated. Among them, a
cross-like resonator easy to achieve dynamic balance is capable of offsetting and broadening the STL
bandwidth, and eliminates node-circle-type oscillation mode. Additionally, a MAM sample whose subresonators are improved in distributions is proposed, wherein the structure and material parameters
of the sub-resonators are symmetrical and interlaced. This sample shows 15 hybrid low-order antiresonance modes within the STL bandwidth, and achieves an excellent ability to insulate the broadband
noise between 48 Hz and 736 Hz. Furthermore, its STL performance could be proved, between 72 Hz and
560 Hz, by a homogeneous ethylene vinyl acetate copolymer plate. Secondly, the coupling characteristics
between this sample and the sound field are revealed in detail, through the analyses of effective parameters, surface-averaged normal displacement, coupled kinetic energy and the coupled vibration behaviors. Finally, the low-frequency STL performance of a large-scale MAM plate sample with one supercell
as a periodic unit is verified by simulation and experiment. This paper proposes a lightweight, flexible
and ultrathin distributed MAM structure that can produce continuous multi-state anti-resonance modes,
which may promote the engineering application investigations of the broadband low-frequency MAMs to
some extent.