Microwave Detection of Longitudinal Crack and Identification of Its Location in Straight Pipe
Microwave Detection of Longitudinal Crack and Identification of Its Location in Straight Pipe
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直管纵向裂纹的微波检测及其位置识别
DOI：
10.1299/jpes.2.538
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
H. Hashizume
中科院分区：
文献类型：
--
作者：
K. Abbasi;S. Ito;H. Hashizume
介绍了一种基于引导电磁波的微波无损检测方法，用于检测钢管纵向裂纹并评估其位置。为了检测管道中的纵向裂纹，应在被检测的有裂纹的管道中传播合适的导模。为此，使用模式转换器将第一个主要循环 TE11 模式发送到系统。模式转换器用于将矩形TE10模式转换为圆形TE11模式。网络分析仪是微波发生器和接收器，旨在处理反射波和发射波的幅度和相位，用于生成连续信号并测量反射系数的幅度。本研究的目的是证明该技术高速检测管道系统中纵向裂纹的能力。更多的重点是通过测量裂纹反射波的飞行时间（TOF）来评估裂纹位置。给出了用于测量波的 TOF 的频域或时域中多个柱塞位置的两个裂纹位置的结果。将TOF的实验结果与计算结果进行比较表明，通过了解反射波的TOF，可以预测裂纹位置。 TOF 的评估结果与计算结果非常吻合，可以估计裂纹位置，误差小于 0.13%。
A microwave NDT method based on guided electromagnetic wave is described in order to detect longitudinal crack and evaluate its location in steel pipe. To detect longitudinal crack in pipe, suitable guided-mode should be propagated in the inspected pipe with crack. For this purpose, first and dominant circular TE11-mode is sent to the system by using a mode-converter. Mode-converter is used to convert rectangular TE10-mode to the circular TE11-mode. A network analyzer, which is a generator and receiver of the microwaves designed to process the magnitude and phase of the reflected and transmitted waves was used to generate continues signal and to measure the amplitude of reflection coefficient. The goal of this investigation is to demonstrate the capability of this technique for detecting longitudinal cracks in piping system with high speed. More emphasis is put on the evaluation of crack location by measuring time of flight (TOF) of the reflected waves from the crack. The results for two crack locations at several plunger positions either in frequency domain or time domain for measuring TOF of the waves are presented. The experimental results of TOF are compared with calculations to show that by knowing TOF of the reflected wave, it is possible to predict crack locations. The evaluated results of TOFs are shown to agree well with the calculated ones and crack locations can be estimated with error less than 0.13%.