论文期刊

An approach to broaden low-frequency bandwidth of sound insulation by regulating dynamic effective parameters of acoustic metamaterials




作者: Guojian Zhou, Jiu Hui Wu, Xiujie Tian, Kuan Lu, Xiao Liang, Wei Huang
发表/完成日期: 2019-02-25
期刊名称: J. Phys. D: Appl. Phys.
期卷: Vol.52, No.21
相关文章: ZhouGuojian_2019_An approach to broaden low-frequency bandwidth of sound insulation by regulating dynamic effective parameters of acoustic metamaterials.pdf   
论文简介
In this paper, an approach is proposed to broaden the low-frequency bandwidth of sound
insulation by regulating dynamic effective parameters of acoustic metamaterials (MAMs).
First, a flexible membrane-type acoustic MAM sample consisting of a homogenous polyimide
membrane and a perforated ethylene vinyl acetate copolymer (EVA) plate is designed, in which
the membrane within each hole is represented as a local resonator without any additional mass.
Next, the formation mechanisms of the trough, peak and bandwidth of sound transmission
loss (STL) are profoundly expounded through the analyses of average normal displacement
(d_z), coupling vibration characteristics and zero-boundary effective parameters. All of this
has shown that the lower limit, peak frequency and upper limit of the STL bandwidth can
be regulated by the vibration modes of the lumped coupling resonance, anti-resonance and
local resonance, respectively. In addition, the structural and material parameters of the MAM
unit are quantitatively analyzed, simultaneously, the regulation approaches of the zeroboundary effective parameters and the transfer characteristics of the STL bandwidth are also
demonstrated. Finally, we have proposed two improved lightweight proposals based on the
broadening mechanisms of the STL bandwidth. The results show that the STL bandwidth can
be greatly broadened between 80 Hz and 800 Hz, and the STL on average is 12.2 dB higher
than that of a homogenous EVA plate. The MAM samples not only provide a suffcient strength
and a long lifecycle, but also help to eliminate the dependence of the membrane tension.