ABSTRACT

This study experimentally investigates the efficacy of TE₁₁ mode microwaves in detecting bend-region cracks. Three types of bends with different dimensions were deployed in a 3 m piping system and then tested, with an axial or circumferential slit machined at different angular positions to simulate a crack. The TE₁₁ mode microwaves were excited using self-designed TE₁₁ mode microwave probes and utilised for crack detection. The experimental results show clear reflection peaks at the bend position, demonstrating the feasibility of applying TE₁₁ mode microwaves in the detection of bend-region cracks. Furthermore, the peak location of reflection is in accordance with the angular position of the slit. The findings also indicate that the peak amplitude of reflection is affected by the factors of mode conversion of microwaves at a bend. In addition, the experimental results also manifest an excellent signal-to-noise ratio to both two types of slits, suggesting that the microwave NDT is a powerful tool for bend-region inspection.

摘要

本研究通过实验研究了 TE ₁₁模式微波在检测弯曲区域裂纹中的功效。三种不同尺寸的弯头被部署在一个 3 m 的管道系统中，然后进行测试，在不同的角度位置加工一个轴向或圆周狭缝来模拟裂缝。TE ₁₁模式微波使用自行设计的 TE ₁₁模式微波探头激发并用于裂纹检测。实验结果显示在弯曲位置有清晰的反射峰，证明了应用 TE _{11的可行性}模式微波在弯曲区域裂纹的检测中。此外，反射的峰值位置与狭缝的角度位置一致。研究结果还表明，反射峰值幅度受弯曲处微波模式转换因素的影响。此外，实验结果还表明两种狭缝都具有出色的信噪比，表明微波无损检测是弯曲区域检测的有力工具。