An evaluation of the conductivity and the radius of metallic rods is conducted by utilizing an analytical model of the surface magnetic field. First, an axisymmetric model of a cylindrical coil encircling a metallic rod is established and an analytical solution for the magnetic induction intensity is derived by means of a separation variable technique and a truncated region technique. The results of the analytical model calculation demonstrate that the radial magnetic induction intensity decreases by different degrees at different axial positions as the conductivity and rod radius increase, whereas the axial magnetic induction intensity increases. Moreover, the closer the radial distance is to the rod, the more obvious the change in the magnetic field will be. The radial magnetic field peak (Br(p)) and the axial magnetic field at zero (Bz(0)) can be used as the characteristic quantities for conductivity and rod radius measurements. Additionally, a butterfly graph is proposed to comprehensively evaluate the effect of conductivity and rod radius on the radial and axial magnetic induction intensities. Most importantly, the calculation results agree well with the numerical simulation, showing that the proposed technique not only illustrates the potential of further development for eddy current testing, but also provides guidance for continued experimental research.
Auld, B.A., and J.C. Moulder, 1999, “Review of Advances in Quantitative Eddy Current Nondestructive Evaluation,” Journal of Nondestructive Evalu-ation, Vol. 18, No. 1, pp. 3–36.
Bilik, Y., D. Bilik, A. Moshkovich, V. Perfilyev, and L. Rapoport, 2011, “Roughness Measurement Parameters by the Eddy Current Technique,” Materials Evaluation, Vol. 69, No. 6, pp. 794–802.
Bowler, J.R., and T.P. Theodoulidis, 2005, “Eddy Currents Induced in a Conducting Rod of Finite Length by a Coaxial Encircling Coil,” Journal of Physics D: Applied Physics, Vol. 38, No. 16, doi.org/10.1088/0022-3727/38/16/019.
Chen, J.Z., 2016, “Inspection Techniques for Tubulars Used in Oilfield,” Materials Evaluation, Vol. 74, No. 10, pp. 1362–1370.
Dodd, C.V., and W.E. Deeds, 1968, “Analytical Solutions to Eddy-Current Probe-Coil Problems,” Journal of Applied Physics, Vol. 39, No. 6, pp. 2829–2838.
Efimov, A.G., 2010, “Development of Adaptive Eddy-Current Instruments for Flaw Sizing,” Russian Journal of Nondestructive Testing, Vol. 46, pp. 780–788.
García-Martín, J., J. Gómez-Gil, and E. Vázquez-Sánchez, 2011, “Non-destructive Techniques Based on Eddy Current Testing,” Sensors, Vol. 11, No. 3, pp. 2525–2565.
Grimberg, R., L. Udpa, A. Savin, R. Steigmann, P. Vizureanu, A. Bruma, and S.S. Udpa, 2008, “Remote Field Eddy Current Control using Rotating Magnetic Field Transducer: Application to Pressure Tubes Examination,” Research in Nondestructive Evaluation, Vol. 19, No. 4, pp. 202–218.
Jiang, F., and S. Liu, 2018, “Evaluation of Cracks with Different Hidden Depths and Shapes Using Surface Magnetic Field Measurements Based on Semi-Analytical Modelling,” Journal of Physics D: Applied Physics, Vol. 51, No. 12, doi.org/10.1088/1361-6463/aaaef9.
Mao, X., and Y. Lei, 2016, “Thickness Measurement of Metal Pipe Using Swept-Frequency Eddy Current Testing,” NDT & E International, Vol. 78, pp. 10–19.
Mueller, E., L. Carney, and K. Mixson, 2018, “Use of Eddy Current Conductivity and Hardness Testing to Evaluate Heat Damage in Aluminum Alloys,” Journal of Failure Analysis and Prevention, Vol. 18, pp. 50–54.
Saludes-Rodil, S., E. Baeyens, and C.P. Rodríguez-Juan, 2015, “Unsuper-vised Classification of Surface Defects in Wire Rod Production Obtained by Eddy Current Sensors,” Sensors, Vol. 15, No. 5, pp. 10100–10117.
Tsukada, K., Y. Haga, K. Morita, N. Song, K. Sakai, T. Kiwa, and W. Cheng, 2016, “Detection of Inner Corrosion of Steel Construction using Magnetic Resistance Sensor and Magnetic Spectroscopy Analysis,” IEEE Transactions on Magnetics, Vol. 52, No. 7, pp. 1–4.
Wang, T., Y. Zhou, C. Lei, J. Luo, S. Xie, and H. Pu, 2017, “Magnetic Impedance Biosensor: A Review,” Biosensors and Bioelectronics, Vol. 90, pp. 418–435.
Ye, C., A. Rosell, and L. Udpa, 2018, “Using Magnetoresistive Sensors in Nondestructive Testing,” Materials Evaluation, Vol. 76, No. 2, pp. 144–154.
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