Impact of Manufacturing Tolerances on Stress in a Turbine Blade Fir-Tree Root

• Autorzy: Moneta Grzegorz , Jachimowicz Jerzy

Identyfikatory

DOI

10.2478/fas-2020-0009

• Języki publikacji: EN

Abstrakty

EN

Low Cycle Fatigue (LCF) is one of most common mechanisms behind turbine blade failures. The reason is high stress concentration in notch areas, like fir-tree root groves, which can cause cyclic stress beyond the safe threshold. The stress levels strictly depend on the manufacturing accuracy of the fir-tree lock (for both fitted together: blade root and disk groove). The probabilistic study aimed at determination of stress was performed using Finite Element Method (FEM) simulation on a population of 1000 turbine models (disk + blades +friction dampers), where fir-tree lock dimensions were sampled according to the normal distribution, within limits specified in the documentation. The studies were performed for different manufacturing quality levels: 3-Sigma, 6-Sigma and 3-Sigma with tolerance ranges reduced twice. Based on the results, the probabilistic distributions, probabilities and expected ranges of values could be determined for: material plastification, stress, strain, LCF lifetime, etc. The study has shown how each tooth of the root is loaded and how wide a stress range should be expected in each groove. That gives information on how the definition of tolerances should be modified to make the construction more optimal, more robust, with lower likelihood of damage, taking into account the cost-quality balance. It also shows how the Six Sigma philosophy can improve the safety of the construction, its repeatability and predictability. Additionally, the presented numerical study is a few orders of magnitude more cost- and time-effective than experiment.

Słowa kluczowe

EN

fir-tree root; turbine; lock; blade; disk; manufacturing tolerances; Monte-Carlo simulations; Six Sigma; Low Cycle Fatigue; Design of Experiment

• Wydawca: Wydawnictwa Naukowe Sieci Badawczej Łukasiewicz - Instytutu Lotnictwa
• Czasopismo: Fatigue of Aircraft Structures
• Rocznik: 2020
• Tom: Iss. 12
• Strony: 92--101
• Opis fizyczny: Bibliogr. 12 poz., rys., tab., wykr.

Twórcy

autor

Moneta Grzegorz

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

• https://orcid.org/0000-0003-3899-1957

autor

Jachimowicz Jerzy

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

• https://orcid.org/0000-0002-0486-6448

Bibliografia

• [1] Arkhipov, A. N., Krasnovskiy, Y. E. and Putchkov, I. V. (2012). Probabilistic life assessment of turbine vanes. Proceedings of the ASME 2011 Turbo Expo: Turbine Technical Conference and Exposition. Volume 6: Structures and Dynamics, Parts A and B. Vancouver, British Columbia, Canada. June 6-10, pp. 733-740. ASME. https://doi.org/10.1115/GT2011-45841.
• [2] Folta, M. and Jachimowicz, J. (1995). Modelowanie w metodzie elementów skończonych tarcz wirników silników turbinowych. Przegląd Mechaniczny, 23/24, 13-18.
• [3] Hall B. D. and Gray L. (2011). Probabilistic high-cycle fatigue risk assessment of an integrally bladed rotor. Proceedings of the ASME 2011 Turbo Expo: Turbine Technical Conference and Exposition. Volume 6: Structures and Dynamics, Parts A and B. Vancouver, British Columbia, Canada. June 6-10, pp. 705-714. ASME. https://doi.org/10.1115/GT2011-45151.
• [4] Jachimowicz, J., Kozłowski, P., Moneta, G., Szymczyk, E. and Kaniowski, J. (2010). Zjawisko frettingu w konstrukcjach lotniczych, Prace Instytutu Lotnictwa, 206, pp. 36-58.
• [5] Jachimowicz J., Navrotski V. and Wawrzyniak A. (1997). Zastosowanie MES w analizach wytrzymałościowych wirników maszyn przepływowych. Przegląd Mechaniczny 71, pp. 10-14.
• [6] Jachimowicz, J., Karliński, W. and Szachnowski, W. (2000). Blade and Disk In-Lock Co-Operation - Selected Problems. Machine Dynamics Problems, 24(4), pp. 71-86.
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• [8] Klepacki W.(1975). Nieklasyczne zagadnienia drgań łopatek turbin lotniczych, PhD Disertation, Institute of Aviation, Warsaw.
• [9] Moneta G., Jachimowicz J., Osiński J. (2014). Influence of Manufacturing Tolerances on Vibration Frequencies of Turbine Blade, Machine Dynamics Research, 38(1), 105-118.
• [10] Peter, J. (1999). The History of Aircraft Gas Turbine Engine Development in the United States ... A Tradition of Excellence, Atlanta, Ga.: International Gas Turbine Institute of the American Society of Mechanical Engineers.
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• [12] Wdowiński, W., Szymczyk, E., Jachimowicz, J. and Moneta, G. (2017). Design and Strength Analysis of Curved-Root Concept for Compressor Rotor Blade in Gas Turbine, Fatigue of Aircraft Structures, 2017, pp. 137-155, https://doi.org/10.1515/fas-2017-001.

Uwagi

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