Flexible planar eddy current probes are widely used to detect conductive components with complex surface. In this study, topological transformation is applied to design a differential Koch coil exciting eddy current probe. Two kinds of Koch exciting coils, Koch A and Koch , were obtained by topological transformation from a three-dimensional differential exciting eddy current probe. Finite element model simulation is conducted to visualize the differences of eddy current distributions induced by the probes and get the defect signal. A detailed comparison is made among the two kinds of Koch eddy current probes and a circular eddy current probe by experiments. The experiments demonstrate that the sensitivity of the Koch A eddy current probe is higher than that of another two probes for detecting the defect which is shorter than the size of the probe. This work provides a novel method for improving the performance of eddy current probes in the coil structure design.

中文翻译：

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一种具有平行绕线拓扑结构的新型平面微分科赫分形涡流探头

柔性平面涡流探头广泛用于检测具有复杂表面的导电部件。在这项研究中，拓扑变换被应用于设计差分科赫线圈励磁涡流探头。两种科赫励磁线圈，科赫A和科赫，是通过从三维差分励磁涡流探头的拓扑变换获得的。进行有限元模型仿真以可视化探头感应的涡流分布差异并获得缺陷信号。通过实验对两种科赫涡流探头和圆形涡流探头进行了详细比较。实验表明，Koch A涡流探头检测缺陷的灵敏度高于另外两种短于探头尺寸的探头。这项工作为提高涡流探头在线圈结构设计中的性能提供了一种新方法。