Abstract In order to study and further develop underwater acoustic absorption structures, we present an underwater metamaterial for broadband acoustic absorption in this study, which is composed of viscoelastic rubber, conical cavity, cylindrical oscillator and backing steel. Basis for design is the contribution of local resonance resonators to low frequency absorption of airborne sound. The accuracy of finite element calculation (FEA) is verified by the theoretical model established by transfer matrix (TM) method at radial coordinates. Relative to pure viscoelastic rubber and traditional cavity acoustic absorption structure, the proposed structure could show excellent broadband acoustic absorption performance below 10 kHz. The geometrical size, shape, and position of filler also affect the direction of shear wave propagation after the transformation, which is critical reason behind the broadband underwater acoustic absorption. Different geometries and material parameters also could adjust the acoustic absorption to a great extent. Underwater impedance tube experiment proves the correctness of the FEA and TM calculation results. These conclusions could potentially be used to the underwater acoustic absorption structure.

中文翻译：

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一种用于低频宽带吸声的水下超材料

摘要 为了研究和进一步开发水下吸声结构，本研究提出了一种用于宽带吸声的水下超材料，它由粘弹性橡胶、锥形腔、圆柱振子和背衬钢组成。设计的基础是局部共振谐振器对空气声的低频吸收的贡献。有限元计算(FEA)的准确性通过径向坐标传递矩阵(TM)法建立的理论模型进行验证。相对于纯粘弹性橡胶和传统的腔体吸声结构，所提出的结构在10 kHz以下表现出优异的宽带吸声性能。几何尺寸、形状、填料的位置和位置也会影响变换后的横波传播方向，这是宽带水声吸收背后的关键原因。不同的几何形状和材料参数也可以在很大程度上调整吸声。水下阻抗管实验证明了FEA和TM计算结果的正确性。这些结论有可能用于水下吸声结构。