电磁热多物理耦合成像检测方法研究

Research on imaging detection method of thermo-electromagnetic multi-physical coupling effects

涡流和热成像检测技术均可应用于导体材料评估和无损探伤。传统的涡流检测系统分辨率低,无法对缺陷轮廓进行精确定量;而传统的热成像系统往往需要大功率的激励装置,且很难消除样件表面杂质或辐射率异常引起的误判。为互补两种检测技术的优势,该文提出一种基于电磁热多物理场耦合效应的成像检测方法。该方法包含一种新型L型磁轭和阵列PCB线圈结构,可通过磁轭激励样件产生的电磁效应和热效应分别对缺陷进行磁成像和热成像,以达到提高检测可靠性的目的。实验结果表明:相比于单一涡流或热成像检测技术,该文所提出的传感结构可显著提高系统的可靠性和可检测性。

Eddy current testing(ET)and thermography(ECT)are both effective non-destructive testing(NDT)methods applied to the evaluation of conductor materials.Conventional ET system has low detection resolution and cannot accurately quantify the contour of defects,while conventional ECT system requires high-power excitation source and it is hard to eliminate the misjudgments caused by impurities or abnormal emissivity on the sample surface.In order to complement the advantages of these two technologies,a novel detection method based on thermo-electromagnetic multi-physical coupling effects is proposed.In this method,a new type of Lshaped magnetic yoke with an array PCB coils structure is included.The electromagnetic and thermal effects generated by the yoke are used for magnetic imaging and thermal imaging of defects respectively,so as to enhance the reliability.The experimental results show that the proposed sensing structure can significantly improve the reliability and detectability of the system compare to single ET or ECT technology.