局域共振型声学超材料及其噪声控制

Noise control of a local-resonant acoustic metamaterials

为实现宽频噪声的控制,提出一种兼有Helmholtz共振和弹簧质量系统共振的声学超材料及其控制方法。将双局域共振系统等效为两个弹簧质量系统的串联,理论计算结果表明双局域共振声学超材料能够产生两个局域共振带隙,有限元仿真验证了所建立数学模型的正确性。在对比分析共振腔腔体体积和薄膜张力对系统传递损失影响的基础上,选择通过气压调整薄膜张力实现系统传递损失的控制。实验结果表明:当驱动气压从0增加至2 kPa时,系统传递损失第一个峰值基本保持不变,第二个峰值向高频偏移150 Hz。所设计的局域共振型声学超材料在带隙范围内对低频噪声具有良好的控制效果,为宽频噪声自适应控制提供了一种方法。

In order to control the wide-band noise,An acoustic metamaterial with both Helmholtz resonance and spring mass system resonance and its control method were proposed..The double local resonance system was equivalent to the series connection of two spring mass systems.Theoretical results showed that two local resonance band gaps can be generated in the double resonance acoustic metamaterials.The correctness of the mathematical model was verified by the Finite Element Method.Based on the comparison of the influences of resonant volume and membrane tension on the transmission loss of the system,the pneumatic modulation was selected to control the tension of the membrane and then the transmission loss.The measurement indicated that,when the driving air pressure increased from 0 to 2 kPa,the first transmission loss peak of the system kept almost constant while the second transmission loss peak shifted 150 Hz to the high frequency.The designed local resonance acoustic metamaterials have good control effect on low-frequency noise in the band gap range,thus providing a method for adaptive control of broadband noise.