The Paton Welding Journal, 2025, №07

2025 №07 (05)

DOI of Article 10.37434/tpwj2025.07.06

2025 №07 (07)

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The Paton Welding Journal, 2025, #7, 37-41 pages

Research of the eddy-current resonance method for measuring the thickness of the carbon fiber reinforced plastic layer on metallic structures

V.M. Uchanin¹, O.G. Aleschenko¹, A. Savin², V.Ja. Derecha³

¹G.V. Karpenko Physico-Mechanical Institute of the NASU 5 Naukova Str., 79060, Lviv, Ukraine. E-mail: vuchanin@gmail.com
²Nondestructive Testing Department, National Institute of Research and Development for Technical Physics, Iasi, Romania
³SE “ANTONOV” 1 Mrija Str., 03062, Kyiv, Ukraine

Abstract
The possibility of non-contact measurement of a carbon fiber reinforced plastic (CFRP) layer on structures made of non-magnetic aluminium alloy and ferromagnetic steel by the eddy current method was investigated. The research was carried out using flat specimens made of aluminium alloy D16T and ferromagnetic steel St20, on which a set of 1 mm thick flat plates made of CFRP were tightly laid. The number of the plates was varied to simulate the different thickness of CFRP layer. Parametric type eddy current probes (ECP) in the form of windings with 300 and 600 turns installed on an 8 mm diameter ferrite core were studied (magnetic permeability — 600). The ECP output voltages were investigated in the resonant mode at operating frequencies of 5, 8.5 and 20 kHz. The obtained dependences of voltage in the resonant circuit on the thickness of the CFRP layer became the basis for development of a device for non-contact measurement of the CFRP layer thickness on products made of aluminium alloys in the range of thicknesses up to 12 mm and ferromagnetic steel in the range of thicknesses up to 15 mm. The ability to measure the CFRP layer on metal structures is relevant not only for non-destructive inspection of their quality during production, but also for monitoring the integrity of such layered structures during their operation. Operational monitoring envisages preliminary determination of the thickness of CFRP layer in the reference points with the purpose of their further use as reference values. An increase in the results of measuring the thickness of the CFRP layer in the reference points during monitoring relative to the reference values will indicate the formation of delamination at the “metal–CFRP” boundary or between individual CFRP layers in operation.
Keywords: carbon fiber reinforced plastic, aluminium alloy, ferromagnetic steel, eddy current probe, thickness measurement, resonant mode, operating frequency

Received: 07.04.2024
Received in revised form: 12.05.2024
Accepted: 09.07.2025

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Suggested Citation

V.M. Uchanin, O.G. Aleschenko, A. Savin, V.Ja. Derecha (2025) Research of the eddy-current resonance method for measuring the thickness of the carbon fiber reinforced plastic layer on metallic structures. The Paton Welding J., 07, 37-41.

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