基于双通道磁传感器的复杂钢结构裂纹信号检测提取方法

Extraction Method of Crack Signal for Inspection of Complicated Steel Structures Using A Dual-Channel Magnetic Sensor.

作者信息

Hayashi Minoru, Saito Taisuke, Nakamura Yoshihiro, Sakai Kenji, Kiwa Toshihiko, Tanikura Izumi, Tsukada Keiji

机构信息

Graduate School of Interdisciplinary Science and Engineering in Health Systems; Okayama University, 3-1-1 Tsushimanaka, Kita-ku, Okayama 700-8530, Japan.

Graduate School of Natural Science and Technology; Okayama University, 3-1-1 Tsushimanaka, Kita-ku, Okayama 700-8530, Japan.

出版信息

Sensors (Basel). 2019 Jul 8;19(13):3001. doi: 10.3390/s19133001.

DOI:10.3390/s19133001

PMID:31288385

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC6651439/

Abstract

Conventional eddy current testing (ECT) using a pickup coil probe is widely employed for the detection of structural cracks. However, the inspection of conventional ECT for steel structures is difficult because of the magnetic noise caused by the nonuniform permeability of steel. To combat this challenge, we have developed a small magnetic sensor probe with a dual-channel tunneling magnetoresistance sensor that is capable of reducing magnetic noise. Applying this probe to a complicated component of steel structures-such as the welds joining a U-shaped rib and deck plate together-requires the reduction of signal fluctuation caused by the distance (liftoff) variations between the sensor probe and the subject. In this study, the fundamental crack signal and the liftoff signal were investigated with the dual-channel sensor. The results showed that the liftoff signals could be reduced and differentiated from the crack signals by the differential parameters of the dual-channel sensor. In addition, we proposed an extraction technique for the crack signal using the Lissajous curve of the differential parameters. The extraction technique could be applied to the inspections not only for flat plates but also for welded angles to detect cracks without the influence of the liftoff signal.

摘要

使用拾波线圈探头的传统涡流检测（ECT）被广泛用于检测结构裂纹。然而，由于钢材磁导率不均匀产生的磁噪声，对钢结构进行传统ECT检测很困难。为应对这一挑战，我们开发了一种带有双通道隧穿磁阻传感器的小型磁传感器探头，该探头能够降低磁噪声。将此探头应用于钢结构的复杂部件，如连接U形肋和桥面板的焊缝，需要减少传感器探头与检测对象之间距离（提离）变化引起的信号波动。在本研究中，使用双通道传感器对基本裂纹信号和提离信号进行了研究。结果表明，通过双通道传感器的差分参数，可以降低提离信号并将其与裂纹信号区分开来。此外，我们提出了一种利用差分参数的李萨如图形提取裂纹信号的技术。该提取技术不仅可以应用于平板检测，还可以应用于角焊缝检测，以在不受提离信号影响的情况下检测裂纹。