A technique for fluoroscopic control and analysis of technical condition of aircraft structural elements with honeycomb filler

Aeronautical and Space-Rocket Engineering

Control and testing of flying vehicles and their systems


Аuthors

Krylov A. A.*, Moskaev V. A.**

Air force academy named after professor N.E. Zhukovskii and Y.A. Gagarin, Voronezh, Russia

*e-mail: Anatoliy_krylov@mail.ru
**e-mail: moskaev82@mail.ru

Abstract

Application of various non-destructive testing (NDT) methods and means in conditions of operation is an effective method for sustaining the required reliability of aerotechnics. The structures with honeycomb filler from aluminum, steel and titanium alloys are employed in the modern aircraft airframes elements. Currently, x-ray method is the most effective one for such structures inspection. The article covers the non-destruction inspection technique performing of the aircraft structural elements with the honeycomb filler, and estimation of the images obtained by the fractal analysis.

The proposed technique consists of three main blocks:

1.   The block forming initial data, restrictions and assumptions:

a)   Variable parameters of the fluoroscopic installation (“Norka” X-ray TV unit);

b)   Invariable parameters characterizing design specifics of aircraft or control object (CO).

2.   A block of the fluoroscopic control methodology of aircraft design elements with honeycomb filler:

a)   A model for images base formation with account for the fluoroscopic installation parameters adjustment:

-     The CO X-raying schemes elaboration;

-    forming the images base when changing the anode voltage value at the emitter and the distance from the emitter to the CO. The best picture of the element with a honeycomb core was obtained in the framework of the experiment at U = 50 kV; F = 90 cm (F is a focal length, U is the anode voltage);

b)     A model for the image quality assessing:

-    Expert evaluation of the images database, with the concordance coefficient calculation [3];

c)     The CO fault detection performing:

-    Parameters adjustment of the “Norka” X-ray TV unit according to the image quality assessment model;

-    The CO fault detection according to the X-raying scheme;

-    The fault detection results decoding and analysis by fractal analysis.

3.   Recommendations formation on fault detection and repair of aircraft structural elements with honeycomb filler.

Fractal dimensions of the honeycomb filler without defects and the one with defects (the presence of moisture and geometry violation of the honeycomb filler structure boundaries) were obtained applying FracLab software.

The result of fractal dimension computing was obtained using the FracLab program by the direct geometric method of counting the cells of the honeycomb filler structure without defect and the one with defect.

The graph deviation of the structure with a defect from the linear dependence, characterizing the self­similarity of the structure under study, is twice as large as on the graph without a defect. It indicates the boundaries structure violation of the honeycomb filler. In addition, the graph with a defect in the double logarithmic coordinates has a kink, characterizing transition between different types of the structure (liquid presence in the honeycomb filler).

The additional information on the state of the system under study can be extracted by determining the self-similarity ranges limits.

Thus, employing the fluoroscopic control technique will allow performing the fault detection inspection of the aircraft structural elements with the honeycomb filler based on fractal analysis, as well as analyzing the obtained images base, and trace the dynamics of the honeycomb filler parameters changes, and defects of its internal structure, while the aircraft operation. However, it should be noted that the fractal analysis may be employed in the long term for automated parameters adjustment of the “Norka” X- ray TV unit, and the images base decoding without an operator.

Keywords:

fluoroscopic control, aircraft, image processing, fractal analysis

References

  1. Sannikov A.V. Nauchnyi vestnik MGTU GA, 2013, no. 192, pp. 124-126.

  2. Gossen S.A. Nauchnyi vestnik MGTU GA, 2006, no. 109, pp. 94-99.

  3. Nebelov E.V., Pototskii M.V., Rodionov A.V., Gorskii A.N. Mechanism of damage propagation to the propeller blades of composite materials with exposed damaging elements. Aerospace MAI Journal, 2016, vol. 23, no. 1, pp. 26-31.

  4. Stepanov A.V. Aviatsionnye materialy i tekhnologii, 2004, no. 2, pp. 81-86.

  5. Klyuev V.V. (editor) Nerazrushayushchii kontrol’. T. 1, kniga 1. Vizual’nyi i izmeritel’nyi kontrol’ (Non­destructive testing. Vol.1, book 1. Visual and measuring control), Moscow, Mashinostroenie, 2008. 323 p.

  6. Nesteruk D.A., Vavilov V.P. Izvestiya Tomskogo politekhnicheskogo universiteta, 2004, vol. 307, no. 6, pp. 62-65.

  7. Nesteruk D.A., Khorev V.S., Korobov K.N. Kontrol’. Diagnostika, 2011, no. 11, pp. 13-16.

  8. Krylov A.A., Chizhov I.A., Zaets N.P. Nauka. Promyshlennost’. Oborona: trudy XV Vserossiiskoi nauchno-tekhnicheskoi konferentsii (Novosibirsk, 23-25 April 2014). Sbornik statei, Novosibirsk, NGTU, 2014, pp. 640-644.

  9. Korobov K.N., Nesteruk D.A. Vestnik nauki Sibiri, 2011, no. 1(1), pp. 193-195.

  10. Nesteruk D.A., Vavilov V.P. Izvestiya Tomskogo politekhnicheskogo universiteta, 2004, vol. 307, no. 6, pp. 62-65.

  11. Gerasimov I.V., Karpenko O.N., Krylov A.A., Kirpichnikov A.P., Oleshko V.S., Tkachenko D.P. Vestnik tekhnologicheskogo universiteta, 2015, vol. 18, no. 5, pp. 158-161.

  12. Kosarina E.I., Stepanov A.V., Tarakanov Yu.V., Usachev V.E. Aviatsionnye materialy i tekhnologii, 2004, no. 2, pp. 73-81.

  13. Maximov N.A., Maluta E.V., Sharonov A.V. Automated system for aircraft failures recorded during preflight inspection recordkeeping. Aerospace MAI Journal, 2015, vol. 22, no. 4, pp. 85-90.

  14. Tits S.N. Vestnik Samarskogo gosudarstvennogo aerokosmicheskogo universiteta, 2008, no. 1, pp. 80-91.

  15. Kochanenko I. Fractal Characteristics of Forcast Properties of Non-linear Regress. – Lecture Notes in Information Technology. Journal of Information Engineering Research Institute, 2012, vol. 13, pp. 192-195.

  16. Kokhanenko I.K., Moskaev V.A. Obozrenie prikladnoi i promyshlennoi matematiki. 2010, vol. 17, no. 4, pp. 568- 570.

  17. Kolmakov A.G., Vstovsky G.V. Multifractal analysis of metallic surface structure changes during mechanical treatment. Materials Science and Technology, 1999, vol. 15, no. 5, pp. 1-6.

  18. Kolmakov A.G., Vstovskii G.V., Bunin I.Zh. Vvedenie v mul’tifraktal’nuyu parametrizatsiyu struktur materialov (Introduction to multifractal parametrization of materials structures), Izhevsk, Nauchno-izdatel’skii tsentr “Regulyarnaya i khaoticheskaya dinamika”, 2001, 116 p.

  19. Programmnyi modul’ FracLac. URL: http://rsb.info.nih.gov/ij/plugins/fraclac/FLHelp/Introduction.htm

  20. Bozhokin S.V., Parshin D.A. Fraktaly i mul’tifraktaly (Fractals and multifractals), Izhevsk, NITs “Regulyarnaya i khaoticheskaya dinamika”, 2001, 128 p.

  21. Moskaev V.A. Izvestiya vysshikh uchebnykh zavedenii. Severo-kavkazskii region. Tekhnicheskie nauki, 2010, no. 2, pp. 88-90.

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