基于声虹吸效应的薄膜声学超材料结构设计与低频吸声性能研究  

Study on the Structural Design and Sound Absorption Properties of Thin-film Acoustic Metamaterials Based on Acoustic Siphon Effect

作　　者：张伟光 刘禧萱 闫宛茹 欧阳玉花[1] ZHANG Weiguang;LIU Xixuan;YAN Wanru;OUYANG Yuhua(School of Mathematics and Physics,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学数理学院,兰州730070

出　　处：《兰州交通大学学报》2024年第4期152-162,共11页Journal of Lanzhou Jiaotong University

基　　金：甘肃省高等学校创新基金(2022A-048);兰州交通大学“天佑青年托举人才计划”基金-第三批。

摘　　要：针对低频噪声防治问题,本文设计了一种薄膜型声学超材料,通过引入质量块自身结构的不对称性,使其在低频范围内形成新的振动模态,实现低频范围内有效控制噪声。所设计单胞结构在200~1000 Hz的范围内存在4个完美吸声峰,吸声系数0.56以上的频带宽度达到350 Hz,平均吸声系数达到0.53。我们通过进一步优化了薄膜超材料的几何参数,并构建了超胞结构,实现声虹吸效应。通过增加不同共振频率的结构单元,使得结构与空气阻抗相匹配,在研究的低频宽带范围内,吸声峰达到10个,最大吸声系数为0.983,平均吸收系数达到0.781,有效拓宽薄膜超材料结构的吸声范围。该研究提升了声学超材料低频吸声效果,为声学超材料结构设计与优化方面提供了解决思路。In response to the problem of low-frequency noise prevention and control, a membrane-type acoustic metamaterial is designed in this paper.By introducing the asymmetry of the mass block's structure, new vibration modes have been formed in the low-frequency range and the noise has been effectively controlled in the low-frequency range.The designed structure of the unit cell has four perfect absorption peaks in the range of 200~1 000 Hz, and the bandwidth of the absorption coefficient above 0.56 reaches 350 Hz, while the average absorption coefficient reaches 0.53.The geometrical parameters of the thin-film metamaterials have been further optimized and the supercell structure has been constructed to realize the acoustic siphon effect.While increasing the number of units with different resonance frequencies, the structure shows a better compatibility with the air impedance, the sound absorption peak reaches 10,the maximum sound absorption coefficient is 0.983,and the average absorption coefficient reaches 0.781 in the studied low-frequency broadband range, which effectively broadens the sound absorption range of the film metamaterial structure.This study enhances the low-frequency sound absorption effect of acoustic metamaterials, providing a solution for improving the low-frequency sound absorption effect of acoustic metamaterials in structural optimization design.

关 键 词：膜型声学超材料 吸声特性 声虹吸效应 低频宽带 

分 类 号：O481.1[理学—固体物理]