Diffusely scattered and transmitted elastic waves by random rough solid-solid interfaces using an elastodynamic Kirchhoff approximation
Diffusely scattered and transmitted elastic waves by random rough solid-solid interfaces using an elastodynamic Kirchhoff approximation
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DOI：
10.1103/physrevb.95.214305
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发表时间：
2017-06-13
影响因子：
3.7
通讯作者：
Craster, Richard
中科院分区：
文献类型：
--
作者：
Shi, Fan;Lowe, Mike;Craster, Richard
由随机粗糙界面散射的弹性波将两种不同的介质分开，在模拟声子散射和影响热传输模型方面起着重要作用，并且也是超声检测的组成部分。我们介绍了弹性波散射场的理论公式，并通过传输，随机粗糙的固体-固体界面使用弹性动力学基尔霍夫近似。通过与数值蒙特卡罗模拟的比较，对宽范围的粗糙度（rms sigma =波长），证明了对广泛使用的小扰动方法的显著改进，小扰动方法仅对具有小RMS值的表面有效。使用这里推导出的理论公式的物理分析表明，增加均方根值导致相当大的变化的散射模式的每一个模式。粗糙度对反射和透射有不同的影响，并与材料性质有很强的依赖性。在两种固体介质的波速完全匹配的特殊情况下，透射率与平坦界面的情况相同。我们特别注意在镜面方向上的散射，通常被用作一个可观察的量，在粗糙度参数方面，在均方根的中间值处显示出一个峰值;这个均方根值与瑞利参数预测的值相吻合。
Elastic waves scattered by random rough interfaces separating two distinct media play an important role in modeling phonon scattering and impact upon thermal transport models, and are also integral to ultrasonic inspection. We introduce theoretical formulas for the diffuse field of elastic waves scattered by, and transmitted across, random rough solid-solid interfaces using the elastodynamic Kirchhoff approximation. The new formulas are validated by comparison with numerical Monte Carlo simulations, for a wide range of roughness (rms sigma = wavelength.), demonstrating a significant improvement over the widely used small-perturbation approach, which is valid only for surfaces with small rms values. Physical analysis using the theoretical formulas derived here demonstrates that increasing the rms value leads to a considerable change of the scattering patterns for each mode. The roughness has different effects on the reflection and the transmission, with a strong dependence on the material properties. In the special case of a perfect match of the wave speed of the two solid media, the transmission is the same as the case for a flat interface. We pay particular attention to scattering in the specular direction, often used as an observable quantity, in terms of the roughness parameters, showing a peak at an intermediate value of rms; this rms value coincides with that predicted by the Rayleigh parameter.