Quantitative damage imaging using Lamb wave diffraction tomography
Quantitative damage imaging using Lamb wave diffraction tomography
复制标题
使用兰姆波衍射断层扫描进行定量损伤成像
DOI：
10.1088/1674-1056/25/12/124304
复制
发表时间：
2016
影响因子：
1.7
通讯作者：
Chai Xiao-Dong
中科院分区：
文献类型：
--
作者：
Zhang Hai-Yan;Ruan Min;Zhu Wen-Fa;Chai Xiao-Dong
本文利用数值模拟产生的转换和非转换散射兰姆波，研究了各向同性板中不同形状的部分穿透孔的衍射层析定量成像损伤。进行有限元模拟以提供散射波数据。通过对圆形盲孔损伤的散射方向图（SDP）的有限元模拟与解析结果的比较，验证了有限元模型的正确性。成像方法基于散射投影的一维（1D）傅立叶变换与散射对象的二维（2D）空间傅立叶变换之间的理论关系。通过对散射体进行二维傅里叶逆变换，得到损伤的定量图像。所提出的方法采用了一个圆形的传感器网络，包含前向和后向投影，这导致所谓的透射模式（TMDT）和反射模式衍射层析成像（RMDT），分别。研究了未转换S 0散射模式的两个投影的重建结果，以说明散射场数据的影响。结果表明，采用TMDT和RMDT相结合的兰姆波衍射层析成像方法比单独使用TMDT或RMDT的成像效果更好。转换后的A0模的散射数据也被用来评估衍射层析成像方法的性能。结果表明，圆形和椭圆形损伤仍能从重建图像中得到较好的识别，而十字形、跑道形等复杂形状损伤的重建效果较差。（专题）
In this paper, we investigate the diffraction tomography for quantitative imaging damages of partly through-thickness holes with various shapes in isotropic plates by using converted and non-converted scattered Lamb waves generated numerically. Finite element simulations are carried out to provide the scattered wave data. The validity of the finite element model is confirmed by the comparison of scattering directivity pattern (SDP) of circle blind hole damage between the finite element simulations and the analytical results. The imaging method is based on a theoretical relation between the one-dimensional (1D) Fourier transform of the scattered projection and two-dimensional (2D) spatial Fourier transform of the scattering object. A quantitative image of the damage is obtained by carrying out the 2D inverse Fourier transform of the scattering object. The proposed approach employs a circle transducer network containing forward and backward projections, which lead to so-called transmission mode (TMDT) and reflection mode diffraction tomography (RMDT), respectively. The reconstructed results of the two projections for a non-converted S0 scattered mode are investigated to illuminate the influence of the scattering field data. The results show that Lamb wave diffraction tomography using the combination of TMDT and RMDT improves the imaging effect compared with by using only the TMDT or RMDT. The scattered data of the converted A0 mode are also used to assess the performance of the diffraction tomography method. It is found that the circle and elliptical shaped damages can still be reasonably identified from the reconstructed images while the reconstructed results of other complex shaped damages like crisscross rectangles and racecourse are relatively poor.(special topics)