Abstract This research develops an underwater acoustic metamaterial, which can serve to absorb broadband low-frequency underwater sound under high hydrostatic pressure ranging from 200 to 2000 Hz. Every unit cell includes 12 harmonic oscillators as multi-scatterers in the proposed acoustic metamaterial, which induces lots of local resonance modes for absorbing sound energy in the investigated frequency range. The sound absorption band can be greatly widened in the low frequency range due to strong coupling and multiple scattering effects among harmonic oscillators. The effectiveness of the prototype is experimentally demonstrated in a standing wave tube under different hydrostatic pressure conditions. The effects of high hydrostatic pressure on local multi-resonance mechanism are investigated experimentally. Experimental results show that the average sound absorption coefficient of the proposed acoustic metamaterial achieves 0.78 in the frequency range [600 Hz, 2000 Hz] under 0.5 MPa. Furthermore, the proposed acoustic metamaterial can achieve better sound absorption performance than the pure viscoelastic polymer under high hydrostatic pressure.

中文翻译：

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高静水压力下水下局部多共振超材料低频吸声实验研究

摘要 本研究开发了一种水声超材料，可用于吸收 200 至 2000 Hz 高静水压力下的宽带低频水声。每个晶胞包括 12 个谐振子作为所提出的声学超材料中的多散射体，这在所研究的频率范围内诱导了许多局部共振模式以吸收声能。由于谐振子之间的强耦合和多重散射效应，在低频范围内可以大大加宽吸声带。在不同静水压力条件下的驻波管中通过实验证明了原型的有效性。实验研究了高静水压力对局部多共振机制的影响。实验结果表明，在 0.5 MPa 下，所提出的声学超材料的平均吸声系数在 [600 Hz, 2000 Hz] 频率范围内达到 0.78。此外，所提出的声学超材料在高静水压力下可以实现比纯粘弹性聚合物更好的吸声性能。