The Paton Welding Journal, 2021, №08



2021 №08 (08)

DOI of Article 10.37434/tpwj2021.08.09

2021 №08 (01)

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The Paton Welding Journal, 2021, #8, 45-51 pages

Eddy current monitoring of aluminium alloy degradation during long-term operation of aircraft

V.M. Uchanin¹, O.P. Ostash¹, S.A. Bychkov², O.I. Semenets² and V.Ya. Derecha²

^lG.V. Каrpеnko Physico-Mechanical Institute of the NAS of Ukraine 5 Naukova Str., 79060, Lviv, Ukraine. E-mail: vuchanin@gmail.com
²Antonov Company 1 Akademika Tupoleva Str., 03062, Kyiv, Ukraine. E-mail: info@antonov.com

Abstract
Monitoring of aluminium alloy degradation is a very important part in ageing aircraft maintenance strategy. Our approach is based on the possibility of finding correlation between the material parameters measurable using nondestructive methods and cyclic crack growth resistance characteristics of the evaluated material. It was revealed that specific conductivity as a structure-sensitive parameter of aluminium alloys, measured by the eddy current method, can be applied as an effective tool for such evaluation. The main advantage of the eddy current method is the possibility to carry out the measurements without a direct contact with the inspected surface. From the point of view of the eddy current method, an aircraft component can be represented by 3-layer object, which consists of dielectric protective coating, anticorrosive layer of about 0.5 mm thickness of pure aluminium cladding and aluminium alloy skin subjected to operational loading. To measure conductivity in this third layer with a high lift-off suppression (up to 0.5 mm), a new eddy current conductivity measuring device of type VEPR-31 was designed. The correlations between elongation, fatigue limit of degraded D16T and B95T1 alloys for different equivalent stresses were obtained. Eddy current measurements of specific conductivity carried out in AN-12 aircrafts (produced in 1966) in different zones of the wing after a long-term operation in aircraft repair plant condition operation confirmed the efficiency of the proposed methodology. 27 Ref., 8 Figures.
Keywords: aircraft, aluminium alloys, degradation, eddy current method, conductivity, fatigue crack growth resistance

Received 22.01.2021

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Suggested Citation

V.M. Uchanin, O.P. Ostash, S.A. Bychkov, O.I. Semenets and V.Ya. Derecha (2021) Eddy current monitoring of aluminium alloy degradation during long-term operation of aircraft. The Paton Welding J., 08, 45-51.

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