长波条件下二维声子晶体中的弹性波传播及各向异性  

The elastic wave propagation in two-dimensional phononic crystal at low frequencies and the anisotropy of effective velocity

作　　者：蔡力[1] 韩小云[1] 温熙森[1] 

机构地区：[1]国防科技大学机电工程研究所,长沙410073

出　　处：《物理学报》2008年第3期1746-1752,共7页Acta Physica Sinica

基　　金：国家重点基础研究发展计划(973)项目(批准号:51307)资助的课题~~

摘　　要：利用多散射方法研究了长波条件下二维声子晶体中弹性波的传播特性.由长波条件下散射体幂散射特性和结构周期特性分析得到了等效波速的解析表达式.通过对幂散射波各阶分波之间由于结构周期特性而产生的耦合作用进行分析,发现幂散射波的正负二阶分量之间的耦合作用具有明显的方向性,长波条件下弹性波的传播特性是否具有各向异性取决于幂散射波的二阶分量在多散射过程中是否有明显的作用.The propagation of elastic waves in two-dimensional phononic crystal is investigated theoretically in the long-wavelength limit by the MST method. Exact analytical formulas for effective velocities of elastic waves are derived according to the behavior of the Mie scattering solution and the lattice sum in the long-wavelength limit. It has been found that the coupling effect between the two second-order components of the cylindrical scattered wave changes with the propagation orientation. Therefore whether the effective velocities of the propagating modes are anisotropic depends on whether the second-order components of the Mie scattering are indispensable.

关 键 词：多散射 各向异性 长波条件 二维声子晶体 弹性波传播 

分 类 号：O73[理学—晶体学]