双锥型五模材料低频声波调控及参数设计

为有效控制噪声并进行声波调控，构造了双锥区域为TC4钛合金、节点区域为硫化橡胶的六边形排列双锥五模材料，进行能带分析发现其具有较窄的低频声子带隙和单模传输区域。为提高五模材料的低频声波调控性能，设计了正方形和三角形排列构型，结果表明三角形排列的双锥五模材料带隙的频率更低，带宽更宽，且具有单模传输性能和较好的五模特性。此外分别探究了五模材料构型的材料参数(包括双锥区和节点区的密度、泊松比和杨氏模量)以及几何参数(包括双锥宽和节点半径的变化)对带隙及单模传输区域的影响，得到带隙和单模传输区的变化规律，选择密度较轻的填充材料、较小的双锥宽和较大的节点半径不仅可以提高低频声波调控性能，而且可以降低结构质量，提高结构的稳定性。该文结果对用于低频声波传播调控的五模材料的构型和参数的设计具有一定的借鉴意义。

Low-frequency sound wave control and parameters design of biconical pentamode materials

In order to control noise and realize sound wave control, based on the common hexagonal configuration, a kind of local resonant biconical pentamode material is designed whose biconical area is filled with TC4 titanium alloy and node area is filled with vulcanized rubber. Band analysis shows that it has narrow phonon band gap and single mode transmission region at low frequency. In order to improve the low frequency acoustic modulation performance of pentamode materials, the square and triangular configurations are designed. The band analysis results show that the biconical pentamode material with triangular configuration has lower band gap frequency, wider bandwidth, single-mode transmission and good pentamode property. The effects of material parameters including density, Poisson''s ratio, Young''s modulus and structural geometric parameters including biconical width and node radius on the band gap and single-mode transmission region are studied respectively. Through obtaining the change law of the band gap and single-mode transmission region, it is found that choosing the filling material with lighter density, smaller bicone width and larger node radius can not only improve the performance of low-frequency acoustic regulation, but also reduce the structure mass and improve the stability of the structure. The results of this paper can be used as a reference for design of the configuration and parameters of the pentamode materials used for regulation on low-frequency acoustic propagation.