Abstract
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 B, 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.
Highlights
As the beginning of obtaining information from eddy current (EC) testing (ECT) instruments, EC probes directly affect the performance of instruments
In order to enrich the information obtained by EC probes, suppress lift-off noise, and improve permeable depth of eddy currents, the waveforms such as dual-frequency [1], multifrequency [2], swept-frequency, chirp [3], pulse [4, 5], and pulse-modulated sine wave [6, 7] were used as the waveforms of an exciting current for EC probes
The method of the coil connection of the differential exciting EC probe has been abstracted to two kinds of topological structures, the series-wound and parallel-wound topological structure, via the geometric transformation method of topology
Summary
As the beginning of obtaining information from eddy current (EC) testing (ECT) instruments, EC probes directly affect the performance of instruments. For detecting the parts with complex shape like cranks and aeroengine blades, flexible planar sensors that can reconstruct the surface to suit the surface of the tested parts were put forward In this way, the shortcomings, which include the area that is hard to reach and the sensors that are influenced by lift-off noise in the conventional rigid sensors, can be improved [17]. With the development of the flexible circuit board technology, it is possible to explore the flexible planar sensors with a complex-shaped coil structure [21] This method is aimed at improving the EC distribution and modulating the defect information of tested parts into the output signals better. A comparative study for the probes is carried out via the finite element model (FEM) simulation and experiments
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
