嵌套型C型管声子晶体低频带隙特性研究

Low-frequency Band Gaps of the Nested C-type Tubes Phononic Crystals

提出了一种由多个C型管嵌套组合而成的二维亥姆霍兹共鸣器型声子晶体结构模型,使用有限元法对所提出结构的能带结构及其产生机理进行了分析。与传统C型管嵌套组合而成的声子晶体结构相比,该结构具有更加优越的低频特性,即可以在50 Hz以下的低频范围内打开带隙。将结构等效为"电感-电容"的等效电路模型,并推导出了带隙估算公式。结果表明,采用有限元法计算得到的带隙与数值估算结果具有较好的一致性。同时研究了主要结构参数对带隙的影响,数值结果表明,通过改变嵌套管数以及填充率等结构参数,能够实现在更宽的频率范围内进行带隙调制。

A two-dimensional Helmhotlz resonator phononic crystal structure composed of nested C-type tubes is proposed.The band gaps and formation mechanism were analyzed using finite element method.Compared with the traditional C-type tubes,the novel structure has better low-frequency characteristics,which can possess band gaps below 50 Hz.The structure was equivalent to the model of inductorcapacitor circuit,and the estimated formula of band gaps were deduced.The results show that the band gaps calculated by the finite element method are consistent with numerical calculations.The effects of structure parameters on the band gaps were studied.The numerical results show that the band gaps can be modulated in an even wider frequency range by changing the structure parameters,such as the number of tubes and the filling rate.