一维准周期声子晶体板中兰姆波的禁带特性分析

Study on the bandgaps of the Lame wave in one-dimensional quasi periodic phononic crystal plates

结合超胞法,利用有限元软件COMSOL计算了兰姆波在一维准周期声子晶体板中的频带结构,研究了其禁带特性和波动局部化现象。讨论了超胞的选取,通过模态图和位移矢量图进行了兰姆波的模态分析;讨论了结构参数和材料参数对兰姆波禁带的影响,其中结构参数包括板厚与晶格常数之比L/D和填充率,材料参数包括组元材料的密度和弹性模量。本文研究结果为实现对兰姆波传播的控制和调节提供新的思路,为准周期声子晶体板用于声学功能器件的设计制作提供一定的理论基础。

Combined with the supercell method,the finite element method was used to study theproperties of band gaps and the localization phenomenon for lamb waves propagating in the one-dimensionalquasi periodic phononic crystal plate.The selection of the size of the supercell was discussed in this paper.The modal analysis of the Lamb waves were studied combined with the modal distributions and displacement vector maps.The influences of the structure and material parameters on the band structure were analyzed.The structure parameters include the ratio of the thickness of the plate to the lattice constant L/Dand the filling rate f.Material parameters were the material densityρand elasticity modulus E.The study provided a new idea for controlling and tuning the propagation of Lamb waves.And this study also gave a certain theoretical guidance for the applying of quasi periodic phononic crystals to acoustic functional devices.