Modular Test Stand for Fatigue Testing of Aeronautical Structures - Verification of Assumptions

• Autorzy: Leski Andrzej , Wronicz Wojciech , Kowalczyk Piotr , Szmidt Michał , Klewicki Robert , Włodarczyk Karol , Uliński Grzegorz

Identyfikatory

DOI

10.2478/fas-2020-0008

• Języki publikacji: EN

Abstrakty

EN

The Modular Test Stand was developed and manufactured to decrease the cost of fatigue testing and reduce the time of its completion as well as to enable testing specimens under more complex load conditions. The stand consists of three connected sections, similar to a wing box, all being loaded in the same way. Thanks to that, several specimens can be tested simultaneously. This configuration requires that stress and strain distribution should be reasonably uniform, as assumed in the design stage. The structure can be loaded with bending or torsion. A whole section, selected structural node or a specimen mounted in the structure as well as a repair or a sensor can be a test object. Two stands, one for bending and one for torsion were prepared. This paper presents the verification of the assumed strain and stress distributions on the skin panels. The measurements were performed with the use of Digital Image Correlation (DIC) as well as strain gauges. DIC measurements were performed on one skin panel of the central section. Five strain gauge rosettes were installed on both panels of the one section. In addition, one rosette was applied to one skin panel in each of two other sections. Measurements were performed on the stand for torsion as well as on the stand for bending. The results of DIC analysis and strain gauge measurement during torsion show uniform shearing strain distributions on the panels. During bending, on the tensioned side, the strains obtained indicate quite uniform strain distributions. On the compressed side, local buckling of the skin panels results in high strain gradients. Strain levels obtained with the use of a DIC analysis and strain gauge measurements were similar. Moreover, horizontal displacements of markers in the spar axis during bending was determined based on a series of photographic. The deflection line obtained in this way has a shape similar to arc, which is characteristic of the constant bending moment. The stand was tested with torsional and bending loads in order to verify the design assumptions. The results of strain distributions on the skin panels with the use of DIC and strain gauges as well as the deflection line of the spar axis indicate that the Modular Test Stand performs as assumed and can be used for tests.

Słowa kluczowe

EN

fatigue; test; airframe; veryfication; strain gauge; DIC

• Wydawca: Wydawnictwa Naukowe Sieci Badawczej Łukasiewicz - Instytutu Lotnictwa
• Czasopismo: Fatigue of Aircraft Structures
• Rocznik: 2020
• Tom: Iss. 12
• Strony: 78--91
• Opis fizyczny: Bibliogr. 13 poz., fot., rys., wykr.

Twórcy

autor

Leski Andrzej

• Military University of Technology, Sylwestra Kaliskiego Str. 2, 00-908 Warsaw

• https://orcid.org/0000-0003-3006-8877

autor

Wronicz Wojciech

• Łukasiewicz Research Network - Institute of Aviation, Krakowska Av. 110/114, 02-256, Warsaw

• https://orcid.org/0000-0002-5580-1329

autor

Kowalczyk Piotr

• Łukasiewicz Research Network - Institute of Aviation, Krakowska Av. 110/114, 02-256, Warsaw

• https://orcid.org/0000-0003-2947-3832

autor

Szmidt Michał

• Łukasiewicz Research Network - Institute of Aviation, Krakowska Av. 110/114, 02-256, Warsaw

• https://orcid.org/0000-0001-7995-594X

autor

Klewicki Robert

• Łukasiewicz Research Network - Institute of Aviation, Krakowska Av. 110/114, 02-256, Warsaw

• https://orcid.org/0000-0002-1809-6632

autor

Włodarczyk Karol

• Łukasiewicz Research Network - Institute of Aviation, Krakowska Av. 110/114, 02-256, Warsaw

autor

Uliński Grzegorz

• Łukasiewicz Research Network - Institute of Aviation, Krakowska Av. 110/114, 02-256, Warsaw

Bibliografia

• [1] Findlay, S. J. and Harrison, N. D. (2002). Why aircraft fail. Materials Today, 5(11), pp. 18-25. https://doi.org/10.1016/S1369-7021(02)01138-0.
• [2] Schijve, J. (2009). Fatigue damage in aircraft structures, not wanted, but tolerated?, International Journal of Fatigue, 31(6), pp. 998-1011. https://doi.org/10.1016/j.ijfatigue.2008.05.016.
• [3] Ansell, H. (2015). Structural Integrity Assessment of Gripen NG Aircraft, in Proceedings 28th ICAF Symposium-Helsinki, Helsinki, pp. 610-624.
• [4] Tsukigase, K., Fukuoka, T., Kumagai, K., Nakamura, T. and Taba, S. (2015). Curved Panel Fatigue Test for MRJ-200 Pressurized Cabin Structure, in Proceedings 28th ICAF Symposium-Helsinki, Helsinki, pp. 276-286.
• [5] Leski, A., Kurdelski, M., Reymer, P., Dragan, K. and Sałaciński, M. (2015). Fatigue Life Assessment of PZL-130 Orlik Structure - Final Analysis and Results, in Proceedings 28th ICAF Symposium-Helsinki, Helsinki, pp. 294-303.
• [6] Brzęczek, J., Gruszecki, H., Pieróg, L. and Pietruszka, J. (2014). Selected Aspects Related to Preparation of a Fatigue Test Plan of a Metallic Airframe. Fatigue of Aircraft Structures, 2014(6), pp. 88-94, https://doi.org/10.1515/fas-2014-0008.
• [7] Rośkowicz, M. and Leszczyński, P. (2017). Evaluation of the Suitability of the Strain-Gauge Method for Measuring Deformations during the Fatigue Tests of Aviation Composite Structures. Fatigue of Aircraft Structures, 2017(9), pp. 75-84. https://doi.org/10.1515/fas-2017-0006.
• [8] Uchanin, V. (2020). Detection of the Fatigue Cracks Initiated near the Rivet Holes by Eddy Current Inspection Techniques, Transactions on Aerospace Research, 2(259), pp. 47-58. https://doi.org/10.2478/tar-2020-0010.
• [9] Leski, A., Szmidt, M. and Wronicz, W. (2019). The modular test stand for fatigue testing of aeronautical structures - Design phase, AIP Conference Proceedings, 2078(1), p. 020021. https://doi.org/10.1063/1.5092024.
• [10] Leski, A., Wronicz, W., Kowalczyk, P. and Szmidt, M. (2020). Conception of Modular Test Stand for Fatigue Testing of Aeronautical Structures. In: Niepokolczycki A., Komorowski J. (eds) ICAF 2019 - Structural Integrity in the Age of Additive Manufacturing. ICAF 2019. Lecture Notes in Mechanical Engineering. Springer, Cham. https://doi.org/10.1007/978-3-030-21503-3_59.
• [11] Sutton, M. A., Orteu, J. J. and Schreier, H. (2009). Image correlation for shape, motion and deformation measurements: basic concepts, theory and applications. Springer Science & Business Media.
• [12] Bajurko, P. (2019). Modelling of the Aerospace Structure Demonstrator Subcomponent, Transactions on Aerospace Research, 1(254), pp. 37-52. https://doi.org/10.2478/tar-2019-0004.
• [13] Łukasiewicz Research Network - Institute of Aviation. Completion of tests of the ILX-34 wing box demonstrator. Jul. 12, 2019. From https://ilot.lukasiewicz.gov.pl/en/completion-of-tests-of-the-ilx-34-wing-box-demonstrator/

Uwagi

1. The authors would like to thank the management of the Materials and Structures Research Centre and the Centre for Composite Technologies of the Łukasiewicz Research Network - Institute of Aviation for enabling this research. The research was financed from the subsidy granted by the Polish Ministry of Science and Higher Education for statutory activities of the Institute of Aviation.

2. Opracowanie rekordu ze środków MNiSW, umowa Nr 461252 w ramach programu "Społeczna odpowiedzialność nauki" - moduł: Popularyzacja nauki i promocja sportu (2021).