| S0兰姆波在渐变折射率声透镜中的聚焦 |
| |
| 引用本文： | 张丽媛,赵金峰,仲政. S0兰姆波在渐变折射率声透镜中的聚焦[J]. 力学季刊, 2016, 37(4): 658-664. DOI: 10.15959/j.cnki.0254-0053.2016.04.005 |
| |
| 作者姓名： | 张丽媛 赵金峰 仲政 |
| |
| 摘 要： | 本文研究了S0兰姆波在渐变折射率声子晶体中的聚焦现象．通过调整正方晶格声子晶体的主轴方向与波传播的相对方向，设计了ΓX和ΓM方向两组不同的渐变折射率声透镜．采用有限单元法模拟S0波在不同声透镜内的传播，并与S0波在声透镜内的传播迹线做了对比，数值结果和理论结果基本一致．数值计算结果显示：ΓX方向的声透镜的焦距fl略大于其理论值，而ΓM方向的声透镜的fl则略小于其理论值．ΓX方向的声透镜的横向分辨率FWHM小于ΓM方向的声透镜，而聚焦强度MFI则大于ΓM方向的声透镜．结果表明，通过调整声子晶体的主轴方向与波传播的相对方向，可以显著地改变声透镜的聚焦特征．这为S0兰姆波声透镜的设计提供了重要依据．
|
| 关 键 词： | 声子晶体 声透镜 S0兰姆波 |
Focusing of the Lowest-Order Symmetric Lamb Wave in Gradient-Index Phononic Crystal Plate |
| |
| ZHANG Li-Yuan,ZHAO Jin-Feng,ZHONG Zheng. Focusing of the Lowest-Order Symmetric Lamb Wave in Gradient-Index Phononic Crystal Plate[J]. Chinese Quarterly Mechanics, 2016, 37(4): 658-664. DOI: 10.15959/j.cnki.0254-0053.2016.04.005 |
| |
| Authors: | ZHANG Li-Yuan ZHAO Jin-Feng ZHONG Zheng |
| |
| Abstract: | In this work, the focalization of the lowest-order Lamb (S0) wave in the gradient-index phononic crystal plate or acoustic lens was investigated. Two kinds of acoustic lenses, namely ΓX or ΓM lenses respectively, were designed by adjusting the principal orientations ΓX or ΓM of phononic crystals relative to the propagation direction of incident waves. The numerical results obtained by the finite element method show good agreement with the theoretical results represented by the ray trajectories of S0 mode in the lenses computed by the geometrical formalism. It shows that the ΓX lens leads to a focal distance larger than its theoretical value while the ΓM lens leads to the contrary. Furthermore, the ΓX lens has a full width at half maximum (FWHM) smaller than the ΓM lens, and a maximum field intensity (MFI) larger than its ΓM counterpart. Both the numerical and theoretical results show that adjusting the principal orientation can effectively affect the characteristics of the focalization of S0 wave, which provides useful suggestions for designing future acoustic lenses. |
| |
| Keywords: | phononic crystals acoustic lens S0 mode |
| 本文献已被 CNKI 等数据库收录！ |
| 点击此处可从《力学季刊》浏览原始摘要信息 |
|
点击此处可从《力学季刊》下载全文 |
