Article Article
Fundamental study for construction of theory for crack detection in dielectric using electromagnetic induction testing

In this paper, a fundamental study was conducted to clarify the principle of crack detection in dielectrics by electromagnetic induction testing (EIT). Simulations and experiments showed that the crack detection principle was different between EIT for conductors (= eddy current testing) and EIT for dielectrics. First, the numerical simulations of cracks in conductors and dielectrics showed that eddy currents and displacement currents formed different current paths around cracks. Next, cracks in conductors and dielectrics were detected using EIT, and it was shown that the locations on the specimen where the EIT output changed were significantly different for conductors and dielectrics. The results showed that the principle of crack detection by EIT for dielectrics was different from that for conductors.


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