二维连接板式声子晶体低频带隙仿真研究

为了能够控制低频噪声,设计了一种二维连接板式声子晶体。运用有限元法计算了该结构的色散曲线及位移场。结果表明,所设计结构在29.37~354.07 Hz存在带隙。与文献模型相比,该结构的起始频率更低,带隙更宽,说明连接板结构声子晶体更容易获得低频带隙。通过位移场的振动模态分析,并结合质量-弹簧模型,解释了带隙产生的原因。在此基础上,讨论了连接板宽度和硅橡胶包覆层开孔半径大小对带隙的影响,随着连接板的宽度减小以及硅橡胶包覆层上孔的半径减小,该结构的带隙逐渐变宽。

Simulation Study of Low Frequency Band Gap for a Two-Dimensional Plate-Connected Phononic Crystal

In order to control low frequency noise, a two-dimensional plate-connected phononic crystal was designed. The dispersion curve and displacement field of the structure were calculated by finite element method. The results show that the designed structure has a band gap between 29.37 Hz and 354.07 Hz. Compared with the model in the literature, this structure has a lower initial frequency and a wider band gap, which indicates that it is more accessible to obtain low frequency band gap in phononic crystals with connecting plate structure. The enlarged band gap was also explained by vibration modal analysis of displacement field and mass spring model. On this basis, the influences of the width of the connecting plate and the opening radius of the silicon rubber coating on the band gap were further discussed. It is noted that as the width of the connecting plate decreases, the band gap can be increased gradually. As the pore radius tapped in the silicon rubber coating decreases, the band gap further increases.