论文标题
雷利波散射的理论和数值建模通过弹性包含
Theoretical and numerical modeling of Rayleigh wave scattering by an elastic inclusion
论文作者
论文摘要
这项工作介绍了通过弹性包含的二维雷利波反向散射的理论和数值模型，宿主材料是各向同性的，并且包含任意形状和晶体学对称性。理论模型是根据远场绿色的函数和天生近似的基于互惠定理开发的，假设宿主和包容材料之间存在较小的声学阻抗差异。建立了数值有限元（FE）模型，以提供对散射问题的相对准确模拟并评估理论模型的近似值。与各向同性/各向异性特性的任意形状的表面/地下夹杂物的理论模型和FE结果之间观察到定量一致。当瑞利波的波长大于包含大小的大小或可比性时，该协议非常出色，但是随着波长变小，它会恶化。同样，该一致性随各向异性指数而减少，以介绍各向异性对称性。结果为使用雷利波（Rayleigh Wave）定量表征表面/地下夹杂物的定量表征奠定了基础，同时也证明了其局限性。
This work presents theoretical and numerical models for the backscattering of two-dimensional Rayleigh waves by an elastic inclusion, with the host material being isotropic and the inclusion having arbitrary shape and crystallographic symmetry. The theoretical model is developed based on the reciprocity theorem using the far-field Green's function and the Born approximation, assuming a small acoustic impedance difference between the host and inclusion materials. The numerical finite element (FE) model is established to deliver relatively accurate simulation of the scattering problem and to evaluate the approximations of the theoretical model. Quantitative agreement is observed between the theoretical model and the FE results for arbitrarily-shaped surface/subsurface inclusions with isotropic/anisotropic properties. The agreement is excellent when the wavelength of the Rayleigh wave is larger than, or comparable to, the size of the inclusion, but it deteriorates as the wavelength gets smaller. Also, the agreement decreases with the anisotropy index for inclusions of anisotropic symmetry. The results lay the foundation for using Rayleigh waves for quantitative characterization of surface/subsurface inclusions, while also demonstrating its limitations.
