NUMERICAL MODELLING OF THE AIRFRAME DAMAGE GROWTH FOR THE ADHESIVE REPAIR JOINT CALCULATION

In the context of the predicted growth in air transportation, the additional attention will be paid to the organization of the competitive maintenance and repair operations for the commercial airplanes. The implementation of new technological processes for airframe repairs and the application of modern information technologies during the development of the repair procedures can be a significant advantage in the expanding market of post-production support of the commercial air fleet. Airframe adhesive repairs allow using lifting abilities of the materials more intensively, but application of the adhesive joints technology requires more complicated strength calculation procedure. It is advisable to utilize the modern finite element software packages to perform the reliable calculation. The capabilities of these software packages allow obtaining adequate computational results for adhesive repair joint parameters subjected to cyclic loads. This paper is concentrated on application of the finite element methods to simulate the crack growth in isotropic material and on methods for accelerated calculation of the mechanical response of cracked structures. Crack growth simulation is performed based on XFEM methods where the created finite element model is complemented with asymptotic imitation function of crack tip and with discontinuous jump function across the crack surfaces. Fatigue properties of the repair joint are modelled in accordance with direct cyclic approach, where a Fourier series approximation with time integration of the nonlinear material behavior is applied. After that, the result of integration at each point of the load history is used for the prediction of the material fatigue properties degradation at the next step of computation; this allows us to evaluate the material damage growth rate. Based on calculation results, a conclusion was made that the received numerical data match the full-scale test results; the time spent for calculation with the usage of accelerated computational methods was evaluated.

1. Harrison, M. (2016). MRO Forecast and Market Trends. Proceeding of IATA 12th Maintenance Cost Conference. Bangkok, 14–15 Sept.

2. Cooper, T., Smiley, J., Porter, C. and Precourt, C. Global Fleet & MRO Market Forecast Summary 2017–2027. Available at: http://www.oliverwyman.com/ourexpertise/insights/2017/feb/2017-2027-fleet-mro-forecast.html (accessed 09.02.2018).

3. Moores, V. (2014). Views Diverge On Bonded Repairs To Primary Composite Structures. AWIN First, Oct 13, 2014. Available at: http://aviationweek.com/mro/views-diverge-bonded-repairsprimary-composite-structures (accessed 09.02.2018).

4. Artyukhin, Y.P. (1973). Napryazheniya v kleevykh soedineniyakh [Stresses in bonded joints]. Issledovanija po teorii plastin i obolochek [Researches on theory of plates and shells], iss. 8, pp. 23–28. (in Russian)

5. Vorobei, V.V. and Sirotkin, O.S. (1985). Soedineniya elementov konstruktsii iz kompozitsionnykh materialov [Joints of structural elements made of composite materials]. Leningrad: Mashinostroenie. (in Russian)

6. Kut'inov, V.F. (1979). Raschet kleevykh soedineni. [Analysis of bonded joints]. Proektirovanie, raschet i ispytaniya konstruktsii iz kompozitsionnykh materilov. Rukovodyashchie tekhnicheskie materialy [Design, analysis and testing of the composite structures. Technical handbook]. Moscow: TsAGI, Iss. 7, pp. 14–31. (in Russian)

7. Semin, M.I. (1982). Proektirovanie kleevykh soedinenii [Design of bonded joints]. Moscow: Mashinostroenie. (in Russian)

8. Khvatan, A.M. (1979). Raschet kleevogo soedineniya s uchetom plastichnosti kleya [Analysis of bonded joint with adhesive plasticity]. Uchenye zapiski TsAGI, vol. X, no. 4, pp. 140–143. (in Russian)

9. Shvechkov, E.I., Kudryashov, A.B. and Khvatan, A.M. (1985). Analiz napryazhennodeformirovannogo sostoyaniya kleevogo soedineniya [Analysis of stress-strain condition of the bonded joint]. Problemy prochnosti, no. 9, pp. 88–92. (in Russian)

10. Turusov, R.A. (2016). Adgezionnaya mekhanika [Adhesive mechanics]. Moscow: NRU MGSU, 228 p. (in Russian)

11. Freidin, A.S. and Turusov, R.A. (1990). Svoistva i raschet adgezionnykh soedinenii [Properties and analysis of adhesive joints]. Moscow: Khimiya. (in Russian)

12. Turusov, R.A. and Manevich, L.I. (2010). Contact layer method in adhesive mechanics. Polymer Science. Series D, vol. 3, no. 1, pp. 1–9.

13. Tomblin, J.S., Salah, L., Welch, J.M. and Borgman, M.D. (2004). Bonded Repair of Aircraft Composite Sandwich Structures. Report DOT/FAA/AR-03/74.

14. Baker, A.A., Rose, L.R.F. and Jones, R. (2002). Advances in the Bonded Composite Repairs of Metallic Aircraft Structure. Elsevier Ltd.

15. Kulikov, V.V. and Petrova, A.P. (2017). Primenenie kleev pri remonte aviatsionnoi tekhniki. (Obzor literatury) [Application of the adhesives for aircraft repairs. (Literature survey)]. Remont. Vosstanovlenie. Modernizatsiya, no. 2, pp. 21–27. (in Russian)

16. Petrova, A.P. and Kulikov, V.V. (2009). Kleevye materialy, ispol'zuemye v remontnovosstanovitel'nykh rabotakh [Adhesive materials used for repair-and-renewal operations]. Remont. Vosstanovlenie. Modernizatsiya, no. 9, pp. 5–14. (in Russian)

17. Petrova, A.P. and Kulikov, V.V. (2009). Properties of adhesive materials used in repairand-renewal operations. Polymer Science. Series D, vol. 2, no. 1, pp. 34–43.

18. Vilents, V.S. (2009). Peculiarities of repairing delamination-lamination-type defects on honeycomb sandwiches made from aluminum alloys and composite materials under operating conditions. Polymer Science. Series D, vol. 2, no. 2, pp. 112–114.

19. Zhadova, N.S., Lukina, N.F. and Tyumeneva, T.Yu. (2012). Samokleyashchiesya materialy dlya vremennogo operativnogo remonta vneshnei poverkhnosti izdelii aviatsionnoi tekhniki [Selfadhesive materials for temporary operative repairs on the outer surface of aircraft structures]. Klei. Germetiki. Tekhnologii, no. 6, pp. 2–4. (in Russian)

20. Kulikov, V.V., Pavlovskaya, T.G., Petrova, A.P. and Zakharov, K.E. (2016). Podgotovka poverkhnosti alyuminievykh splavov pri provedenii remonta aviatsionnoi tekhniki s primeneniem kleev [Surface preparation of the aluminum alloys for aircraft bonded repairs]. Remont. Vosstanovlenie. Modernizatsiya, no. 2, pp. 14–17. (in Russian)

21. Kulikov, V.V., Aleksashin, V.M., Antyufeeva, N.V., Petrova, A.P. and Sharova, I.A. (2017). Issledovanie protsessa otverzhdeniya epoksidnogo kleya VK-27 na poverkhnosti fenol'nokauchukovogo kleevogo podsloya VK-25 [Research of the curing process of epoxy adhesive VK-27 on the surface of phenolic-rubber adhesive sublayer of VK-25]. Klei. Germetiki. Tekhnologii, no. 4, pp. 2–5. (in Russian)

22. Sharova, I.A., Kulikov, V.V., Petrova, A.P. and Shuklina, O.A. (2016). Vliyanie podsloya fenol'no-kauchukovykh kleev na svoistva epoksidnogo kleya kholodnogo otverzhdeniya VK-27 i ego modifikatsii pri provedenii remonta aviatsionnoi tekhniki [Effect of phenolic-rubber adhesive sublayer on the properties of the low-temperature cure epoxy adhesive VK-27 and it’s modifications for aircraft repairs purposes]. Klei. Germetiki. Tekhnologii, no. 10, pp. 18–21. (in Russian)

23. Nesterenko, B.G. (2010). Crack resistance of skin materials for civil airplane structures. Scientific Bulletin of the Moscow State Technical University of Civil Aviation, no. 153, pp. 7–14. (in Russian)

24. Belytschko, T. and Black, T. (1999). Elastic crack growth in finite elements with minimal remeshing. International Journal for Numerical Methods in Engineering, vol. 45, no. 5, pp. 601–620.

25. Moës, N., Dolbow, J. and Belytschko, T. (1999). A finite element method for crack growth without remeshing. International Journal for Numerical Methods in Engineering, vol. 46, no. 1, pp. 132–150.

26. Sukumar, N., Moës, N., Moran, B. and Belytschko, T. (2000). Extended finite element method for three-dimensional crack modelling. International Journal for Numerical Methods in Engineering, vol. 48, no. 11, pp. 1549–1570.

27. Duong, C.N. and Wang, C.H. (2004). On the characterization of fatigue crack growth in one-sided bonded repair. Journal of Engineering Materials and Technology, vol. 136, pp. 192–198.