系统频率电磁调谐的双层薄膜声学超材料
Double-layer membrane acoustic metamaterial with electromagnetic tunable frequency
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摘要: 为了拓宽声学超材料对低频声波的隔声带宽,设计了1种系统频率电磁调谐的双层薄膜声学超材料,该超材料由双层硅橡胶薄膜、薄膜之间的羰基铁粉、附加铅质质量块、铝质框架和电磁场加载装置等组成.运用COMSOL Multiphysics 5.5仿真和试验等方法,对声学超材料的声学性能进行了研究.研究结果表明:该声学超材料在低频范围内可实现良好的隔声效果;通过输入不同电流改变磁场强度,可以实现声学超材料固有频率的定向调节;与被动声学超材料相比,主动声学超材料实现了声学超材料隔声性能的非接触主动调谐,拓宽了声学超材料的声波控制带宽;在此基础上,通过进一步探讨材料参数对声学超材料声学性能的影响,发现双层薄膜的厚度越厚,杨氏模量越大,声学超材料将获得更宽的隔声带宽.Abstract: To broaden the sound insulation bandwidth of acoustic metamaterials in low frequency sound waves, a double-layer membrane acoustic metamaterial with electromagnetic tunable frequency was designed, which was composed of a double-layer membrane, carbonyl iron powder between membranes, additional lead, aluminum frame and electromagnetic field loading device. The acoustic performance of the acoustic metamaterial was investigated by COMSOL Multiphysics 5.5 simulation software and experiment methods. The results show that the acoustic metamaterial can achieve good sound insulation effect in low frequency range, and the natural frequency of the acoustic metamaterial can be achieved by changing magnetic field strength with inputting different currents. Compared with passive acoustic metamaterials, the non-contact active control of sound insulation performance of the acoustic metamaterials can be achieved by directional adjustment, and the sound wave control bandwidth of the structure can be broadened. The influence of material parameters on the acoustic properties of acoustic metamaterials illuminates that with the increasing of double-layer membrane thickness, the Young′s modulus is increased, and the acoustic metamaterial can obtain wider sound insulation bandwidth.