Superwide-angle acoustic propagations above the critical angles of the Snell law in liquid—solid superlattice
Superwide-angle acoustic propagations above the critical angles of the Snell law in liquid—solid superlattice
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DOI：
10.1088/1674-1056/23/12/124301
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发表时间：
2014-10
影响因子：
1.7
通讯作者：
Sai Zhang;Yu Zhang;Xiao-Tian Gao
中科院分区：
文献类型：
--
作者：
Sai Zhang;Yu Zhang;Xiao-Tian Gao
本文研究了液-固超晶格中Snell定律临界角以上的超广角声传播。入射波超过斯涅耳定律的临界角通常不可避免地引起全反射。然而，大倾角入射波通过液-固超晶格时，在一定频率范围内会产生超广角透射，不会发生全反射。结合有限元模拟和传输矩阵法理论分析，认为兰姆波的布拉格散射是声波超传播的物理机制。入射角、填充率和材料厚度对传播有显著影响。超广角传播现象在层状结构的无损检测和能流控制方面具有潜在的应用价值。
In this paper, superwide-angle acoustic propagations above the critical angles of the Snell law in liquid—solid superlattice are investigated. Incident waves above the critical angles of the Snell law usually inevitably induce total reflection. However, incident waves with big oblique angles through the liquid—solid superlattice will produce a superwide angle transmission in a certain frequency range so that total reflection does not occur. Together with the simulation by finite element analysis, theoretical analysis by using transfer matrix method suggests the Bragg scattering of the Lamb waves as the physical mechanism of acoustic wave super-propagation far beyond the critical angle. Incident angle, filling fraction, and material thickness have significant influences on propagation. Superwide-angle propagation phenomenon may have potential applications in nondestructive evaluation of layered structures and controlling of energy flux.