准一维声子晶体中兰姆波低频禁带特性研究  

Low-frequency band gap performance for Lamb waves in quasi-one-dimensional phononic crystal

作　　者：丁红星[1,2] 戴丽莉[2] 沈中华[1] 陆建[1] 倪晓武[1] 

机构地区：[1]南京理工大学理学院,江苏南京210094 [2]连云港师范高等专科学校物理与电子工程系,江苏连云港222006

出　　处：《南京理工大学学报》2013年第6期869-874,共6页Journal of Nanjing University of Science and Technology

基　　金：国家自然科学基金(11274175;61108013);高等学校博士学科点专项科研基金(20103219120040);江苏省高校“青蓝工程”(2012)

摘　　要：为了优化一维声子晶体薄板中的兰姆波禁带结构,在薄板侧面基体组元中嵌入空气圆孔,构建了准一维声子晶体系统。运用超原胞平面波展开法和有限元法计算了空气圆孔半径对禁带结构的影响,分析了空气圆孔对特征模式位移场的扰动效应,研究了空气柱散射体对该声子晶体兰姆波带隙结构的优化作用。结果表明:随着空气圆孔半径的增加,同模式兰姆波间的耦合作用显著增强,完全禁带数量和宽度因此明显增加,其在0~4 MHz低频范围内的占有比例可以提高至70%左右。To optimize the band gap structure of Lamb waves in one-dimensional( 1D) phononic crystal( PC) thin plates,quasi-1D PC thin plates are established by embedding a row of air holes periodically in the matrix components in one side of the plate. The effects of the holes' radii on the band gap of the quasi-1D PC thin plates are calculated by using the super cell plane wave expansion method and finite element method. The disturbance effects of the embedded air scatterers on the displacement field of the eigenmodes are analyzed. The optimizion of air column scatterers on this phononic crystal Lamb wave band gap structure is researched. The results show that with the increaseof the radii of the air holes,the coupling between the same lower-order mode Lamb waves is enhanced significantly,the number and bandwidths of the band gaps are increased significantly too,and the occupation ratio of the forbidden gaps in the 0-4 MHz low frequency range is about 70%.

关 键 词：兰姆波 声子晶体 低频 禁带 超原胞平面波展开法 有限元法 

分 类 号：N55[自然科学总论]