In addition to the accelerated deterioration of structures built during the period of rapid economic growth, there is a growing need for simpler and more advanced infrastructure degradation diagnostic technologies due to a shortage of inspection personnel. To address these needs, our laboratory is developing a magnetic non-destructive testing system that uses highly sensitive magnetic sensors to detect wall thinning and cracks in steel materials. Furthermore, we are elucidating electromagnetic phenomena within steel materials through electromagnetic field analysis (computer simulation) using the finite element method.

While eddy current testing is generally used for surface inspection, testing at low frequencies makes it possible to detect defects on the reverse side as well.

 

Schematic diagram of eddy current testing

Eddy Current Testing Equipment for Detecting Back-Surface Defects and Its Experimental Results [1]

Results of magnetic field analysis using the finite element method [2]

参考文献

[1] W. Yoshimura, T. Sasayama,and K. Enpuku,"Optimal Frequency of Low-Frequency Eddy-Current Testing for Detecting Defects on the Backside of Thick Steel Plates," IEEE Trans. Magn. vol. 55, no. 7, 2019. DOI: 10.1109/TMAG.2019.2896590

[2] T. Sasayama, T. Ishida, M. Matsuo, and K. Enpuku, "Thickness measurement of an iron plate using low frequency eddy current testing with an HTS coil," IEEE Trans. Appl. Supercond., vol. 26, no. 5, Art. no. 9001305, 2016. DOI: 10.1109/TASC.2016.2535366

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Last Update: April 24, 2026