Mussatayev Meirbek, Kempka Ruby, Alanesi Mohammed
School of Electrical, Electronic and Mechanical Engineering, University of Bristol, Bristol BS8 1TR, UK.
Kazakhstan Institute of Non-Destructive Evaluation LLP, 59, Tole bi Street (KBTU), Almaty 050005/A05H1T2, Kazakhstan.
Sensors (Basel). 2024 Oct 18;24(20):6702. doi: 10.3390/s24206702.
In the field of railroad safety, the effective detection of surface cracks is critical, necessitating reliable, high-speed, non-destructive testing (NDT) methods. This study introduces a hybrid Eddy Current Testing (ECT) probe, specifically engineered for railroad inspection, to address the common issue of "lift-off noise" due to varying distances between the probe and the test material. Unlike traditional ECT methods, this probe integrates transmit and differential receiver (Tx-dRx) coils, aiming to enhance detection sensitivity and minimise the lift-off impact. The study optimises ECT probes employing different transmitter coils, emphasising three main objectives: (a) quantitatively evaluating each probe using signal-to-noise ratio (SNR) and outlining a real-time data-processing algorithm based on SNR methodology; (b) exploring the frequency range proximal to the electrical resonance of the receiver coil; and (c) examining sensitivity variations across varying lift-off distances. The experimental outcomes indicate that the newly designed probe with a figure-8 shaped transmitter coil significantly improves sensitivity in detecting surface cracks on railroads. It achieves an impressive SNR exceeding 100 for defects with minimal dimensions of 1 mm in width and depth. The simulation results closely align with experimental findings, validating the investigation of the optimal operational frequency and lift-off distance for selected probe performance, which are determined to be 0.3 MHz and 1 mm, respectively. The realisation of this project would lead to notable advancements in enhancing railroad safety by improving the efficiency of crack detection.
在铁路安全领域，有效检测表面裂纹至关重要，这需要可靠、高速的无损检测（NDT）方法。本研究引入了一种专门为铁路检测设计的混合涡流检测（ECT）探头，以解决由于探头与测试材料之间距离变化而产生的“提离噪声”这一常见问题。与传统的ECT方法不同，该探头集成了发射线圈和差分接收（Tx-dRx）线圈，旨在提高检测灵敏度并最小化提离影响。该研究对采用不同发射线圈的ECT探头进行了优化，重点关注三个主要目标：（a）使用信噪比（SNR）对每个探头进行定量评估，并概述基于SNR方法的实时数据处理算法；（b）探索靠近接收线圈电共振的频率范围；（c）研究不同提离距离下的灵敏度变化。实验结果表明，新设计的带有8字形发射线圈的探头在检测铁路表面裂纹时显著提高了灵敏度。对于宽度和深度最小为1mm的缺陷，其信噪比超过100，令人印象深刻。模拟结果与实验结果紧密吻合，验证了对所选探头性能的最佳工作频率和提离距离的研究，确定分别为0.3MHz和1mm。该项目的实现将通过提高裂纹检测效率在增强铁路安全方面取得显著进展。
