2021 №09 (07) DOI of Article
2021 №09 (01)

The Paton Welding Journal 2021 #09
The Paton Welding Journal, 2021, #9, 49-55 pages

Three-dimensional visualization of the detected defects by eddy current computing tomography

O.O. Vertiy1 and V.M. Uchanin2

1National Aerospace University «Kharkiv Aviation Institute» 17 Chkalov Str., 61070, Ukraine. E-mail:
2G.V. Karpenko Physico-Mechanical Institute of NASU 5 Naukova Str., 79060, Lviv, Ukraine. E-mail:

Nondestructive computing tomography methods based on different physical phenomena are reviewed as an effective tool to solve many NDT problems in the context of NDE 4.0 revolution. Eddy current (EC) tomography principle and experimental set-up are presented to demonstrate the possibility to reconstruct tomography images related to the distribution of material electric conductivity. A riveted joint of two aluminium alloy sheets with 2 mm long artificial cracklike defects was selected as an example of complex enough inspected structure. Investigations were carried out with two types of eddy current probes (ECP) application: the first one — the traditional EC probe of absolute type with coaxial driving and sensing coils, and the second — low-frequency double differential EC probe of MDF 1201 type. The set of vertical (orthogonal to the inspected surface) slices for the rivet zone were obtained to demonstrate the effectiveness of EC tomography. The horizontal slices were analyzed to demonstrate the possibility to produce tomography images at different depths. Two-layer structures, consisting of upper sheets with thicknesses from 0 to 8 mm and 5 mm thick lower sheath with a cracklike defect were applied to reconstruct the vertical tomography slices using double differential EC probes. The latter results demonstrate the great depth of evaluation with application of ECP of double differential type and the possibility to estimate the detected defect size and distance from the inspected surface. 34 Ref., 8 Figures.
Keywords: eddy current (EC) tomography, eddy current probe (EC probe), double differentiation EC probe, electric conductivity, tomography images, slices, riveted joints

Received 18.03.2021


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