Siquan Zhang, Nathan Ida

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Electromagnetic NDT methods and in particular eddy currents play an important role in nondestructive testing of conducting materials. In testing conductive structures, rectangular coils are often more useful than circular coils. A particular configuration consists of two rectangular coils located above the conductive plates, one placed parallel to the plates serving as an excitation coil and the other perpendicular to the plates serving as a sensing coil. In this work we derive analytical expressions for the induced voltage variations in the pick-up coil. Then the influences of the plate thickness, the exciting frequency and the moving speed of the conductor on the induced voltage variation are analyzed. The analytical calculation results are verified using the finite element method.


Eddy current testing, Conductive plates, Rectangular coil, Induced voltage, Finite element method

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