弹性波斜入射声子晶体的传输特性

Transfer Characteristic of Phononic Crystal during Elastic Wave Oblique Incidence

引入四维波矢的概念,推导出弹性波斜入射到多层介质系统的转移矩阵以及透射系数和反射系数公式。利用这些公式计算了横波和纵波斜入射一维声子晶体时横波和纵波的透射系数,得出横波斜入射,透射波中的横波和纵波在一定频率范围内都会出现禁带,纵波斜入射时也有类似的结果。透射波中横波与纵波的相互转型随着入射角的增大而越加明显。

Introducing four-dimensional wave vector,the transfer matrix and the reflection and transmission coefficients of the multilayers are inferred.With the transfer matrix,the transmission coefficient of the longitudinal wave and transversal wave in one-dimensional phononic crystal is evaluated.It is found that forbidden band appears after transversal or longitudinal wave oblique incidence,the greater the incident angle,the more obvious transformation between the longtitudinal and transversal waves.