ABSTRACT

Defects caused by a harsh working environment and cyclic loading may seriously lead to catastrophic industrial accidents. Therefore, an efficient and accurate detection method is needed to quantitatively characterise the multiple defects of large-area metal components. In this paper, a pulsed eddy current (PEC) array is designed by considering mutual electromagnetic influence between the PEC array; the differential peak values at different scan positions are abstracted as feature signals for defect characterisation, and the relationship between defect width and detection signal is discovered; the detection capability of sensor array for adjacent defects is analysed. Subsequently, the electromagnetic imaging is applied to visualise and quantitatively evaluate the multiple defects, and then, the quantitative detection approaches for the localisation and width of multiple defects in metal components are proposed. An experimental setup is built and the proposed approach is validated by experiment. The results show that the proposed method can effectively determine the locations and widths of defects in metal components within the absolute error of 1 scan step.

摘要

恶劣的工作环境和循环载荷造成的缺陷可能会严重导致灾难性的工业事故。因此，需要一种高效准确的检测方法来定量表征大面积金属部件的多种缺陷。本文通过考虑PEC阵列之间的相互电磁影响，设计了一种脉冲涡流（PEC）阵列；提取不同扫描位置的差分峰值作为特征信号进行缺陷表征，发现缺陷宽度与检测信号的关系；分析了传感器阵列对相邻缺陷的检测能力。随后，应用电磁成像对多个缺陷进行可视化和定量评估，然后，提出了金属部件多个缺陷的定位和宽度的定量检测方法。建立了一个实验装置，并通过实验验证了所提出的方法。结果表明，所提出的方法可以在1个扫描步长的绝对误差范围内有效地确定金属部件中缺陷的位置和宽度。