An approach to reduce lift-off noise in pulsed eddy current nondestructive technology
An approach to reduce lift-off noise in pulsed eddy current nondestructive technology
复制标题
脉冲涡流无损技术中降低提离噪声的方法
DOI：
10.1016/j.ndteint.2013.12.012
复制
发表时间：
2014-04-01
影响因子：
4.2
通讯作者：
Zhang, Dejun
中科院分区：
文献类型：
--
作者：
Yu, Yating;Yan, Yue;Zhang, Dejun
脉冲涡流检测技术作为涡流检测技术中的一种新兴技术，因其具有丰富的时域和频域信息，已广泛应用于飞机、油气管道、核蒸汽管道、高速铁路等工程领域。然而，剥离噪声，引入不同的涂层厚度，不规则的样品表面或传感器的移动，有严重的影响，在这些关键结构中的缺陷的检测精度。这极大地限制了PEC在定量无损检测中的应用。为了减小剥离效应的影响，对剥离效应进行了理论分析和实验研究，在研究差分信号峰值与剥离效应关系的基础上，提出了一种减小剥离噪声的方法，用于缺陷深度或宽度的检测。在该方法中，缺陷深度和宽度由差信号的峰值和剥离的线性曲线的斜率确定。实验结果表明，该方法能有效地降低光电转换技术中的提离噪声。因此，它可以应用于非铁材料样品表面缺陷的表征。(C)2014爱思唯尔有限公司版权所有。
The pulsed eddy current (PEC) technique, as an emerging technique of the eddy current technique, has been used in engineering, such as aircrafts, oil/gas pipelines, nuclear steam pipes and high-speed rails, due to its richer information in time domain and frequency domain. However, the lift-off noise, introduced by varying coating thicknesses, irregular sample surface or movement of transducers, has a serious influence on the accuracy of the detection for the defects in these key structures. It greatly limits the application of PEC in quantitative nondestructive testing. In order to reduce the effect of the lift-off, the lift-off effect is analyzed theoretically and experimentally; based on the investigation of the relationship between the peak value of the difference signal and the lift-off, an approach to reduce the lift-off noise for detection the defect depth or width is proposed. In this approach, the defect depth and width are determined by the slope of the linear curve of the peak value of the difference signal and the lift-off. The proposed approach is verified by experiment and the results indicate that it can highly reduce the lift-off noise in the PEC technique. Therefore, it can be applied in characterization of the surface defects in sample with non-ferrous material. (C) 2014 Elsevier Ltd. All rights reserved.