Magnetic NDE using spectrum analysis of changes in induced voltage at pickup coil and magnetic flux density

Issue title: 20th International Symposium on Applied Electromagnetics and Mechanics

Guest editors: Theodoros Theodoulidis, Christos Antonopoulos, Nikolaos Kantartzis, Ioannis Rekanos and Theodoros Zygiridis

Article type: Research Article

Authors: Kikuchi, Hiroaki^a;

Affiliations: [a] Faculty of Science and Engineering, Iwate University, 4-3-5 Ueda, Morioka, Japan E-mail: [email protected]

Correspondence: [*] E-mail: [email protected]

Abstract: Magnetic nondestructive evaluation (NDE) for ferromagnetic steel using spectrum analysis of induced voltage at a pickup coil and magnetic flux density has been studied. A voltage induced at the pickup coil was measured, and the corresponding magnetic flux density was calculated. Then, their frequency spectrums were obtained through a Fourier analysis. For deformed specimen, higher harmonic components decrease as compared with undeformed specimen. The wave distortion factor for the induced voltage and the magnetic flux density were defined and evaluated. Those values decrease with increasing reduction ratio of the specimen; this means the waveforms of induced voltage and magnetic flux density for a less deformed specimen has a large distortion in those waves. Those changes reflect a nonlinearity of the magnetization curves of the specimen. The results in this study indicate a potential of magnetic NDE using spectrum analysis of measurement wave forms.

Keywords: Magnetic NDE, harmonic, spectrum, distortion factor

DOI: 10.3233/JAE-220134

Journal: International Journal of Applied Electromagnetics and Mechanics, vol. 71, no. S1, pp. S135-S141, 2023