薄膜型声学超材料微结构参数对其隔声性能的影响

摘要

基于有限元法(FEA)计算描述薄膜型声学超材料隔声性能的一个重要表征参量,即传递损失(TL).在此基础上,探索薄膜型声学超材料传递损失峰值(谷值)对应的频率与整个薄膜超材料系统的固有频率之间的关联,并通过调整薄膜声学超材料的微结构特征如薄膜厚度、中心质量块、预应力等参量,研究薄膜型声学超材料固有频率和传递损失峰值(谷值)频率频段之间的关系.主要结论是:薄膜边缘预应力增大则传递损失峰值(谷值)对应频率增大,薄膜厚度增加则传递损失的第二和第三峰值对应的频率降低,而薄膜胞元中心质量块质量大小仅对第一峰值(谷值)对应的频率产生显著的影响.%Abstact :The transmission loss (TL), which is an important characteristic parameter describing insulation properties of thin-films of acoustic meta-materials, is calculated based on finite element method (FEA). On this basis, the relationship between the frequencies at the TL peaks (valleys) and the intrinsic frequencies of the whole system of the membrane-type acoustic meta-materials is discussed. Through adjusting the structure parameters of the thin film such as the membrane thickness, mass of the center metal block and the initial stress in the membrane, the relationship between the intrinsic frequencies of the system and the frequency band at the TL peaks (valleys) is investigated. It is concluded that the corresponding frequencies of the TL peaks (valleys) increase with the increase of the tensile force on the membrane edge, and the frequencies corresponding to the transmission losses of the second peak and the third peak decrease with the increase of membrane thickness. And the mass of the central mass block has significant influence on the frequency corresponding to the first peak (valley).