Print

2021 №08 (08) DOI of Article
10.37434/tpwj2021.08.09 		2021 №08 (01)

The Paton Welding Journal 2021 №08


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

References

1. McMaster, R.C., McIntire, P. (1986) Nondestructive Testing Handbook. Vol. 4: Electromagnetic testing (Eddy current, flux leakage and microwave nondestructive testing). USA, American Society for NDT.
2. Dorofeev, A.L., Kazamanov, Yu.G. (1980) Electromagnetic testing. Moscow, Mashinostroenie [in Russian].
3. Uchanin, V.M. (2006) Eddy current testing of structure elements. Fiz.-Khim. Mekhanika Materialiv, 4, 66-73 [in Ukrainian]. https://doi.org/10.1007/s11003-006-0106-5
4. Dobmann, G., Boller, Ch., Herrmann, H.-G. Altpeter, I. (2014) Micromagnetic and electromagnetic NDT for lifetime management by monitoring ageing of structural materials. Int. J. Microstructure and Materials Properties, 9(3-5), 348-359. https://doi.org/10.1504/IJMMP.2014.066915
5. Estorff, U., Davies, L., Trampus, P. Eds. (1999) In: Proc. of the Joint EC-IAEA Meeting on NDT Methods for Monitoring Degradation. Petten, European Commission, JRC Institute of Advanced Materials.
6. Ostash, O.P., Fedirko, V.M., Uchanin, V.M. et al. (2007) Fracture mechanics and strength of materials. Vol. 9: Strength and fatigue life of aircraft materials and structure elements. Lviv, Spolom [in Ukrainian].
7. Ostash, O.P., Andrejko, I.M., Golovatyuk, Yu.V. (2006) Degradation of materials and fatigue strength of aircraft structures in long-term operation. Fiz.-Khim. Mekhanika Materialiv, 4, 5-16 [in Ukrainian]. https://doi.org/10.1007/s11003-006-0098-1
8. Nesterenko, G.I., Basov, V.N., Nesterenko, B.G., Petrusenko, V.G. (2006) Influence of long-term service of aircraft on properties of materials of their structures. Problemy Mashinostroeniya i Nadyozhnost Mashin, 4, 41-50 [in Russian].
9. Ostash, O.P., Kiva, D.S., Uchanin, V.M. et al. (2012) Diagnostics of technical condition of aircraft structures after long-term operation. Tekh. Diagnost. i Nerazrush. Kontrol, 2, 15-22 [in Russian].
10. Ostash, O., Uchanin, V., Semenets, O., Holovatyuk, Y., Kovalchuk, L., Derecha, V. (2018) Evaluation of aluminium alloys degradation in aging aircraft. Reseach in Nondestructive Evaluation, 29(3),156-166. http:/dx.doi.org/10/1080/093498 47.2017.1302622. https://doi.org/10.1080/09349847.2017.1302622
11. Uchanin, V., Ostash, O. (2019) Development of electromagnetic NDT methods for structural integrity assessment. Procedia Structural Integrity, 16, 192-197. https://doi.org/10.1016/j.prostr.2019.07.040
12. Uchanin, V., Ostash, O., Nardoni, G., Solomakha, R. (2020) Coercive force measurements for structural health monitoring. In: The Fundamentals of Structural Integrity and Failure. Ed. by Richard M. Wilcox. New York, Nova Science Publishers.
13. Uchanin, V.M., Ostash, O.P. (2019) Evaluation of operational degradation of structural materials by electromagnetic methods of nondestructive testing. In: Proc. of 9th Nat. Sci.-Techn. Conf. on Nondestructive Testing and Technical Diagnostics (Kyiv, 21.11.2019), 35-40 [in Ukrainian].
14. Uchanin, V.M., Rybachuk,V.G., Kulynych, Ya.P. Eddy current method for measurement of parameters of electrical conductivity anisotropy of nonferromagnetic materials. Pat. 138680, Ukraine, Int. Cl. G01 N27/90. Publ. 10.12.2019
15. Dorofeev, A.L., Ershov, P.E. (1985) Physical fundamentals of electromagnetic structuroscopy. Novosibirsk, Nauka [in Russian].
16. Naumov, N.M., Miklyaev, P.G. (1974) Resistometric nondestructive testing of aluminium wrought alloys. Moscow, Metallurgiya [in Russian].
17. Rummel, W.D. (1966) Characterization and evaluation of 2014 aluminium alloy by eddy current conductivity techniques. Materials Evaluation, 14(6), 322-326.
18. Bakunov, A.S. (2004) Evolution of equipment for eddy current structuroscopy of nonferrous metals in Russia. Kontrol. Diagnostika, 4, 63-64 [in Russian].
19. Nazarchuk, Z.T., Uchanin, V.M., Kulynych, Ya.P. (2019) Optimization of eddy current testing parameters of degradation changes in specific conductivity of aluminium alloys of aging aircraft. Vidbir i Obrobka Informatsii, 47, 5-11 [in Ukrainian]. https://doi.org/10.15407/vidbir2019.47.005
20. Uchanin, V.N., Makarov, G.N. (1996) Suppression of influence of gap in contactless measurement of specific conductivity by eddy current method. Tekh. Diagnost. i Nerazrush. Kontrol, 4, 41-45 [in Russian].
21. Uchanin, V.M. (2012) Method for measurement of electrical conductivity of nonmagnetic materials. Pat. 98206, Ukraine. Publ. 25.04.2012 [in Ukrainian].
22. Uchanin, V.M., Cherlenevskyi, V.V. (2011) Device for eddy current testing of parameters of products. Pat. 58670, Ukraine. Publ. 26.04.2011 [in Ukrainian].
23. Uchanin, V.M., Makarov, G.M. Cherlenevskyi, V.V. (2012) Eddy current specific conductivity meter of nonferromagnetic materials. Pat. 97304, Ukraine. Publ. 10.01.2012 [in Ukrainian].
24. Ostash, O.P., Andrejko, I.M., Markashova, L.I. et al. (2013) Influence of long-term operation on structure and physicomechanical properties of aluminium alloys of D16 and B95 type. Fiz.-Khim. Mekhanika Materialiv, 49(1), 18-27 [in Ukrainian]. https://doi.org/10.1007/s11003-013-9578-2
25. Ostash, O.P., Uchanin, V.M., Andrejko, I.M., Golovatyuk, Yu.V. (2013) Eddy current method for determination of operation degradation degree of structural materials. Pat. 101424, Int. Cl. G01N27/90. Publ. 25.03.2013 [in Ukrainian].
26. Ostash, O.P., Uchanin, V.M., Andrejko, I.M. et al. Eddy current method of determination of local degradation degree of structural materials during long-term operation. Pat. 106168, Ukraine, Int. Cl. G01N27/90. Publ. 12.05.2014 [in Ukrainian].
27. Ostash, O.P., Uchanin, V.M., Semenets, O.I. et al. (2017) Method of monitoring of local degradation degree of materials of aircraft structures in long-term operation. Pat. 113736, Ukraine, Int. Cl. G01N27/90. Publ. 10.02.2017 [in Ukrainian].