弹性波在准周期镜像固/液声子晶体中的透射

基于准周期Fibonacci序列,构建了准周期镜像结构固液介质声子晶体。利用转移矩阵法,数值研究了弹性波在其中的透射。弹性波正入射时,在奇数序列镜像声子晶体透射谱的带隙内出现多个谐振模,而在偶数序列镜像声子晶体透射谱的带隙内仅有弱透射峰;上、下带边的谐振随序列数的增加而增强。弹性波斜入射时,透射谱向高频区移动;入射角较小时,谐振模也向高频区移动,同时产生了次级禁带;入射角较大时,带隙内的谐振模消失,带隙间的频率间距减小。

The Transmission of Elastic Wave in Quasi Periodic Mirrored Structure Phononic Crystal Composed of Solid and Liquid

On basis of quasi periodic Fibonacci sequence, the mirrored structure phononic crystal composed solid and liquid is proposed. The transmission of proposed structure is investigated with transfer matrix method. For elastic wave normal incident, the resonant modes exist in the band gap of odd order mirrored phononic crystal, while in the band gap of even order mirrored phononic crystal, there exist only weak transmission peaks. Simultaneously, the resonance in the vicinity of upper and lower band edge is enhanced with increase of the sequence order. Moreover, for elastic wave oblique incident, the transmission spectrum shifts to high frequency region. For elastic wave at small incident angle, the resonant modes also shift to high frequency region, the mini band gap appears at the same time. Furthermore, for elastic wave at large incident angle, the resonant modes disappear and the interval of band gaps decrease.