This paper reports an experimental study on a cavity-type metamaterial for broadband sound absorption to break the one-to-one correspondence between back cavity and absorption peak. An acoustic valve composed of a thin plate and a concentrated mass was proposed to pass and block specific frequency sound waves. The results indicate that under the action of the acoustic valve, the unit cell of the metamaterial can obtain more absorption peaks than the number of physical back cavities. Finite element simulation shows that this mechanism can be attributed to acoustic split-frequency multiplexing in the back cavity. Specific parameters for the unit cell are optimized based on genetic algorithms. The consistent finite element simulation and experimental results indicate that the metamaterial with the acoustic valve can achieve efficient absorption performance at 150–550 Hz with a thickness-to-wavelength ratio of 1/28. This study provides valuable design strategies for cavity-type metamaterials to achieve broadband sound absorption.

中文翻译：

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通过声分频复用对空腔型超材料进行频带优化


本文报道了一种用于宽带吸声的空腔型超材料的实验研究，以打破后腔与吸收峰之间的一一对应关系。提出了一种由薄板和集中质量组成的声阀来传递和阻挡特定频率的声波。结果表明，在声阀的作用下，超材料晶胞可以获得比物理背腔数量更多的吸收峰。有限元模拟表明，这种机制可归因于后腔的声学分频复用。基于遗传算法优化晶胞的具体参数。有限元模拟和实验结果一致表明，带有声阀的超材料可以在150-550 Hz的厚度与波长比为1/28的情况下实现高效的吸声性能。这项研究为空腔型超材料实现宽带吸声提供了有价值的设计策略。