两边支撑声学超材料板的低频宽带隔声性能研究

以电力变压器低频隔声为应用背景,提出了一种结构简单轻质的局域共振声学超材料板,它由在两边支撑框架上紧密粘贴高分子聚合物薄板制成,相比四边支撑超材料板,其具有更加优越的低频隔声能力。在声波垂直入射条件下,采用有限元仿真对其隔声特性进行研究,结果表明在248 Hz处出现了一个明显的隔声峰,隔声量达到了31 dB。为拓宽低频隔声频带,在超材料板上布置质量块,仿真结果表明在152~560 Hz范围内出现了三个密集的隔声峰,最高隔声量达26 dB,从而一定程度上实现宽频隔声效果;同时在120 Hz处出现了一个隔声量为18 dB的隔声峰。最后搭建了基于小型箱体的隔声实验平台,可以发现实验测试结果与仿真结果具有较好的一致性,从而验证了轻质声学超材料板良好的低频宽带隔声性能,说明了两边支撑声学超材料板具有广阔的工程化应用前景。

Low frequency broadband sound insulation performance of an acoustic metamaterial panel supported on two sides

Uner the background of the low-frequency sound insulation of power transformers, a kind of simple and lightweight local resonant acoustic metamaterial panel was proposed, which was made by closely bonding high-polymer sheets on the two sides of supporting frames, with a superior low frequency sound insulation capability compared with four-side supported metamaterial panels.Under the normal incident sound wave, the sound insulation performance was studied by finite element analysis (FEA).The results show that there is obvious sound transmission loss (STL) with a peak of 31 dB at 248 Hz.To broaden the STL low-frequency band, mass blocks were arranged on the metamaterial panel.The FEA results show that there are three STL peaks in the range of 152-560 Hz, with the highest STL of 26 dB, thus achieving broadband sound insulation effect to some extent.At the same time, a STL peak of 18 dB appears at 120 Hz.Finally, a sound insulation experiment platform based on small box was built, and it can be found that the experimental test results are in good agreement with the FEA results, which verifies the excellent low-frequency broadband sound insulation ability of the lightweight acoustic metamaterial panel, indicating the acoustic metamaterial panel supported on two sides has broad engineering application prospects.