镶嵌薄膜结构的低频吸声特性分析与实验研究

发布时间：2018-08-21 14:14

【摘要】：为了对低声压级、低频带声波达到理想的吸收效果,提出了一种金属片镶嵌薄膜的复合吸声结构。分析了复合结构局域共振机理:通过薄膜材料的弹性波与每个结构单元的共振特性相互作用,可以产生局域共振带隙,从而使薄膜中的行波不能进行传播。利用传递矩阵法计算了镶嵌结构与薄膜空腔结构结合后的声阻抗,得到理论的吸声系数。通过试验得到复合结构中结构单元和薄膜的阻尼系数与弹性系数,对复合结构进行吸声系数测试,与理论计算值进行对比,理论计算结果与试验吸声系数吻合较好。采用薄膜两侧镶嵌结构单元与一侧的进行试验比较,得到两侧镶嵌结构的吸收峰值附近频带较宽,一些吸声系数达到0.95,实现了低频噪声的高效吸收。
[Abstract]:In order to achieve an ideal absorption effect for low sound pressure and low frequency band sound waves, a composite sound absorption structure of metal embedded thin films was proposed. The mechanism of local resonance of composite structure is analyzed. The local resonance band gap can be produced by the interaction between elastic wave of thin film and resonance characteristic of each structural unit, thus the traveling wave in the film can not be propagated. The acoustic impedance of the mosaic structure combined with the thin film cavity structure is calculated by the transfer matrix method, and the theoretical sound absorption coefficient is obtained. The damping coefficient and elastic coefficient of the structure element and film in the composite structure are obtained by experiments. The sound absorption coefficient of the composite structure is measured and compared with the theoretical calculation value. The theoretical calculation results are in good agreement with the experimental sound absorption coefficient. The experimental results show that the absorption peak of the two sides of the mosaic structure is wider than that of the one side, and some sound absorption coefficients are up to 0.95.The high efficiency absorption of low frequency noise is realized.
【作者单位】：军械工程学院车辆与电气工程系;陆军北京军事代表局驻七四三厂代表室;
【基金】：武器装备“十二五”预先研究项目(51312060404)
【分类号】：TB535.1

【相似文献】