局域共振型空腔覆盖层的低频吸声机理及调控规律研究  

Study on Low Frequency Sound Absorption Mechanism and Regulation Laws of Local Resonant Cavity Coatings

作　　者：王佳蓓 周浩[1] WANG Jiabei;ZHOU Hao(College of Weapons Engineering,Naval University of Engineering,Wuhan 430033,China)

机构地区：[1]海军工程大学兵器工程学院,武汉430033

出　　处：《噪声与振动控制》2022年第2期34-39,共6页Noise and Vibration Control

基　　金：国家自然科学基金资助项目(11602300)。

摘　　要：声学覆盖层的低频吸声特性对潜艇声隐身性能具有重要影响。综合考虑空腔型覆盖层结构和局域共振型薄膜材料的低频吸声性能,建立局域共振型空腔覆盖层的有限元模型,研究复合结构在10 Hz~2 000 Hz频段内的吸声特性,并采用局域共振理论和模态分析揭示复合结构的吸声机理,进一步得到复合结构低频吸声性能的调控规律。研究结果表明:(1)在10 Hz~2 000 Hz频率范围内,相比空腔型覆盖层,复合结构的平均吸声系数提高到0.497;(2)复合结构的低频吸声机理为:通过下半部分空腔变形实现纵波向横波的转化,通过局域共振结构的反共振消耗声能,二者共同作用,提高吸声系数;(3)耦合产生的吸声峰峰值主要随覆盖层损耗因子的增大而增大,峰值频率主要随薄膜面积的增大而向高频移动。研究结果可为声学覆盖层的低频吸声特性设计提供理论指导。It is of great significance to study the low frequency acoustic absorption characteristics of acoustic coatings for improving the acoustic stealth performance of submarines. Comprehensively considering the low frequency sound absorption performances of the cavity type layer structure and local resonance type thin film material, the finite element model of the composite local resonant cavity coating is established, and the sound absorption properties of the composite coating structure are studied in 10 Hz-2 000 Hz frequency range. Using the local resonance theory and modal analysis, the sound absorption mechanism of the composite structure is revealed, further the regulation law of low frequency sound absorption characteristics of the composite structure is achieved. The results show that:(1) In the frequency band of the study, the composite structure of the cavity type coating and the local resonance type thin film material can increase the average sound absorption coefficient to 0.497 in comparison with the cavity type coating;(2) The sound absorption mechanism of the composite structure is that the deformation of the lower part cavity can realize the transformation of P-wave to S-wave, and the antiresonance effect of the local resonance structure consumes sound energy. The two factors work together to raise the sound absorption coefficient;(3) The sound absorption peak generated by coupling mainly increases with the increase of the coating loss factor, and the frequency of sound absorption peak mainly moves to the high frequency side with the increase of the film area. The research results may provide a theoretical guidance for the design of low frequency acoustic absorption characteristics of acoustic coatings.

关 键 词：声学 局域共振 空腔覆盖层 低频特性 振动模态 吸声系数 

分 类 号：O422.4[理学—声学]