Development of attenuation and diffraction corrections for linear and nonlinear Rayleigh surface waves radiating from a uniform line source
Development of attenuation and diffraction corrections for linear and nonlinear Rayleigh surface waves radiating from a uniform line source
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开发从均匀线源辐射的线性和非线性瑞利表面波的衰减和衍射校正
DOI：
10.1063/1.4948259
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发表时间：
2016-04-01
期刊：
影响因子：
1.6
通讯作者：
Li, Xiongbing
中科院分区：
文献类型：
--
作者：
Jeong, Hyunjo;Zhang, Shuzeng;Li, Xiongbing
在最近对非线性瑞利表面波的研究中，谐波产生测量被成功地用于表征材料的损伤和微观结构的变化，并且被发现对损伤过程的早期阶段很敏感。推导了瑞利面波的非线性参数，并对其进行了频繁的测量，以量化损伤程度。精确测量非线性参数一般需要对光束衍射和介质衰减进行修正。对于非线性瑞利波，这些效应通常不为人所知，因此在以前的大多数研究中都没有适当地考虑这些影响。本文从平面波位移解出发，定义了瑞利面波的非线性参数。我们明确定义了均匀线源辐射的基频和二次谐瑞利波光束的衰减和绕射修正。衰减改正由平面瑞利波方程的拟线性理论得到。为了得到绕射修正的闭式表达式，采用多高斯光束(MGB)模型来表示从无抛物线近似的全二维波动方程的拟线性理论得到的积分解。给出了几种发射机-接收机几何结构的绕射修正，并通过对固体样品中非线性参数测定的模拟研究了衰减和绕射修正的影响。
In recent studies with nonlinear Rayleigh surface waves, harmonic generation measurements have been successfully employed to characterize material damage and microstructural changes, and found to be sensitive to early stages of damage process. A nonlinearity parameter of Rayleigh surface waves was derived and frequently measured to quantify the level of damage. The accurate measurement of the nonlinearity parameter generally requires making corrections for beam diffraction and medium attenuation. These effects are not generally known for nonlinear Rayleigh waves, and therefore not properly considered in most of previous studies. In this paper, the nonlinearity parameter for a Rayleigh surface wave is defined from the plane wave displacement solutions. We explicitly define the attenuation and diffraction corrections for fundamental and second harmonic Rayleigh wave beams radiated from a uniform line source. Attenuation corrections are obtained from the quasilinear theory of plane Rayleigh wave equations. To obtain closed-form expressions for diffraction corrections, multi-Gaussian beam (MGB) models are employed to represent the integral solutions derived from the quasilinear theory of the full two-dimensional wave equation without parabolic approximation. Diffraction corrections are presented for a couple of transmitter-receiver geometries, and the effects of making attenuation and diffraction corrections are examined through the simulation of nonlinearity parameter determination in a solid sample.