Dispersion and Attenuation of Surface Acoustic Waves of Various Polarizations on a Stress-Free Randomly Rough Surface of Solid
Dispersion and Attenuation of Surface Acoustic Waves of Various Polarizations on a Stress-Free Randomly Rough Surface of Solid
复制标题
不同偏振表面声波在无应力随机粗糙固体表面上的色散和衰减
DOI：
--
复制
发表时间：
1995
期刊：
影响因子：
--
通讯作者：
A. Shchegrov
中科院分区：
文献类型：
--
作者：
V. Kosachev;A. Shchegrov
摘要 提出了一种在各向异性弹性介质的无应力、随机粗糙表面上获得声表面波（SAW）色散方程的方法。该问题通过使用格林函数技术近似弱粗糙表面来解决。针对各向同性介质的三维 (3D) 和二维 (2D) 粗糙表面，对矢状和水平剪切 (SH) 偏振 SAW 的色散和衰减进行了分析和数值研究。 2D 粗糙度的结果显示包含在 3D 情况的更通用表达式中，并指出了 3D 和 2D 情况的结果之间的联系。推导出两种偏振的 SAW 沿着二维粗糙表面在任意方向上传播的色散关系。在不同的入射角下研究了 SAW 衰减机制。结论是，瑞利和 SH 偏振 SAW 在某些入射角下涉及所有三种机制（即散射成体横向、纵向和瑞利表面声波），而在其他角度仅涉及部分机制。考虑了粗糙表面上 SH 偏振 SAW 存在的标准。讨论了与平坦边界相比，粗糙表面上的 SAW 相速度可能增加的情况。在极限 λ ⪢ a（其中 a 是粗糙度相关长度）下，导出了瑞利和 SH 偏振 SAW 的相速度的简单显式表达式。本文将获得的结果与其他工作人员的结果进行比较。
Abstract An approach to obtaining the dispersion equation of surface acoustic waves (SAWs) on a stress-free, randomly rough surface of an anisotropic elastic medium is suggested. The problem is solved in the approximation of a weakly rough surface using Green′s function technique. The dispersion and attenuation of sagittally and shear horizontally (SH) polarized SAWs are investigated both analytically and numerically for a three-dimensionally (3D) and a two-dimensionally (2D) rough surface of an isotropic medium. The results for 2D roughness are shown to be contained in the more general expressions for the 3D case, and the connection between the results for the 3D and the 2D cases is pointed out. Dispersion relations are derived for SAWs of both polarizations propagating in an arbitrary direction along a 2D rough surface. The SAW attenuation mechanisms are investigated at various incidence angles. It is concluded that all three mechanisms (viz. scattering into bulk transverse, longitudinal, and Rayleigh surface acoustic waves) are involved for the Rayleigh and SH polarized SAWs at certain incidence angles, whereas at the other angles only some of the mechanisms are. The criterion for the existence of SH polarized SAWs on a rough surface is considered. A possible increase of the SAW phase velocity on a rough surface compared with that for a flat boundary is discussed. In the limit λ ⪢ a (where a is the roughness correlation length) simple explicit expressions for the phase velocities of Rayleigh and SH polarized SAWs are derived. A comparison of the results obtained herein with those of other workers is presented.