Wavenumber Imaging of Near-Surface Defects in Rails using Green's Function Reconstruction of Ultrasonic Diffuse Fields
Wavenumber Imaging of Near-Surface Defects in Rails using Green's Function Reconstruction of Ultrasonic Diffuse Fields
复制标题
使用超声波漫射场的格林函数重建对钢轨近表面缺陷进行波数成像
DOI：
10.3390/s19173744
复制
发表时间：
2019-09-01
期刊：
影响因子：
3.9
通讯作者：
Zhu, Qi
中科院分区：
文献类型：
--
作者：
Zhang, Hui;Zhang, Haiyan;Zhu, Qi
利用波数成像结合绿色函数重建超声扩散场，实现钢轨近表面缺陷的快速成像。超声相控阵因其灵敏度高、灵活性强等优点在工业中得到了广泛的应用。然而，直接测量的信号总是被采集系统的物理限制所引起的噪声所复杂化。为了克服这个问题，由探头捕获的扩散场信号的互相关被执行以重建绿色函数。这些重构信号可以从噪声中恢复早期的时间信息。对钢轨近表面缺陷进行了试验研究。实验结果证实了互相关法重构绿色函数用于近表面缺陷检测的有效性。采用不同类型的超声相控阵探头对钢轨表面进行了实验数据采集。绿色函数的恢复与相控阵阵元数和激励频率有关。此外，时间窗扩散信号的持续时间和开始时间进行了探索，以实现高质量的缺陷图像。
Wavenumber imaging with Green's function reconstruction of ultrasonic diffuse fields is used to realize fast imaging of near-surface defects in rails. Ultrasonic phased array has been widely used in industries because of its high sensitivity and strong flexibility. However, the directly measured signal is always complicated by noise caused by physical limitations of the acquisition system. To overcome this problem, the cross-correlations of the diffuse field signals captured by the probe are performed to reconstruct the Green's function. These reconstructed signals can restore the early time information from the noise. Experiments were conducted on rails with near-surface defects. The results confirm the effectiveness of the cross-correlation method to reconstruct the Green's function for the detection of near-surface defects. Different kinds of ultrasonic phased array probes were applied to collect experimental data on the surface of the rails. The Green's function recovery is related to the number of phased array elements and the excitation frequency. In addition, the duration and starting time of the time-windowed diffuse signals were explored in order to achieve high-quality defect images.