一维杆状Thue-Morse(TM)准周期结构声子晶体带隙特性的研究

提出了一维杆状TM准周期结构声子晶体模型,采用有限元法计算了其带隙特性并与周期结构进行了比较。研究表明,TM序列准周期结构声子晶体可以有效地拓宽带隙宽度且能降低起始频率,而且在带隙范围内产生了具有高品质因子的局域共振模;此外还发现,不同代次的TM序列、不同排序的材料组合都不影响其带隙范围,但改变材料参数(密度和弹性模量)却能改变其带隙范围。此研究可供其在减振降噪、滤波、波导等方面的设计和实际应用参考。

Band Gap Characteristics of Thue-Morse(TM) One Dimensional Rod Phononic Crystal with Quasi-Periodic Structure

The model of the TM 1D rod phononic crystal with quasi-periodic structure is proposed.Sections 1 and 2 of the full paper calculate its band gap characteristics using FEM,and compare them with those of periodic structure.Section 1 briefs the band gap characteristics of TM sequence.Section 2 discusses the various factors affecting band gap characteristics.The study shows that the TM phononic crystal with quasi-periodic structure can increase the band gap width and lower the beginning frequency effectively.Most importantly,localized resonant modes appear in the band gap,as shown in Figs.2 through 6.Neither different generations of the TM sequence nor combination of different materials in order can affect its band gap range.The band gap range can be changed with changing the material parameters,such as density and elastic modulus.This study we believe is useful in problems such as vibration and noise reduction,filter,waveguide,etc.