INVESTIGATION OF TIME AND FREQUENCY DOMAIN FATIGUE LIFE CALCULATION METHODS USING FINITE ELEMENT METHOD

Öz

There are several vibration induced fatigue damage and life calculation methods in time domain and frequency domain. These methods with the use of finite element method play important role in mechanical design process. In this study, Rainflow counting method and Dirlik counting method are investigated using finite element method and it is found that Dirlik method gives minimum fatigue life. If there is not an option to validate the design with tests and the only way to evaluate the design is the finite element analysis, Dirlik method is advantageous because it gives the safest design.   

Anahtar Kelimeler

• Rainflow Counting,Dirlik Method,Vibration Fatigue,Random Vibrations,Fatigue

ZAMAN VE FREKANS DÜZLEMİNDE YORULMA ÖMRÜ HESAPLAMA YÖNTEMLERİNİN SONLU ELEMANLAR YÖNTEMİ İLE İNCELENMESİ

Öz

Maruz kalınan titreşim nedeni ile meydana gelen yorulma hasarı ve ömrünü tespit etmek için zaman düzleminde ve frekans düzleminde hesaplama yapan yöntemler bulunmaktadır. Bu yöntemler sonlu eleman analizleri ile birlikte kullanılarak mekanik tasarımın şekillendirilmesi sürecinde kritik rol oynamaktadır. Bu çalışmada zaman düzleminde yorulma hesaplayan Rainflow yöntemi ve frekans düzleminde yorulma hesaplayan Dirlik yöntemi sonlu elemanlar analizleri yardımı ile incelenmiş ve minimum yorulma ömrünü Dirlik metodunun verdiği görülmüştür. Herhangi bir test ile tasarım doğrulama imkânı bulunmadığında ve tasarım yalnızca sonlu elemanlar yöntemi ile değerlendirileceğinde, Dirlik metodu sonuçları referans alınarak yapılacak tasarımın en güvenli tasarımı vereceği için en avantajlı yöntem olduğu tespit edilmiştir.

Anahtar Kelimeler

• Rainflow Yöntemi,Dirlik Yöntemi,Titreşim Kaynaklı Yorulma,Rastlantısal Titreşim,Yorulma

Kaynakça

1. Al-Bahkali, E., Elkenani, H., Souli, M., 2014. Fatigue life estimate of landing Gear’s leg using modal analysis, International Journal of Multiphysics, 8 (2), 231-244.
2. Anonim, 1996. ASM Handbook Fatigue and Fracture Volume 19, ASM International, U.S.
3. ASTM E1049-85, 2017. Standard Practices for Cycle Counting in Fatigue Analysis, ASTM International, West Conshohocken, PA.
4. Benasciutti, D., Sherratt, F., Cristofori, A., 2016. Recent developments in frequency domain multi-axial fatigue analysis, International Journal of Fatigue, 91 (2), 397-413.
5. Bendat, J.S., 1964. Probability Functions for Random Responses: Prediction of Peaks, Fatigue Damage, and Catastrophic Failures. NASA Contractor Report, U.S.
6. Bishop, N., Sherratt, F., 2000. Finite Element Based Fatigue Calculations, NAFEMS, U.K.
7. Cooley, J. W., Tukey, J.W, 1965. An Algorithm for the Machine Calculation of Complex Fourier Series, Mathematics of Computation, 19 (90), 297-301.
8. Dirlik, T., 1985. Application of computers to fatigue analysis, Doktora Tezi, University of Warwick.

9. Fatemi, A., Yang., L., 1998. Cumulative fatigue damage theories: a survey of state of the art for homogenious materials, International Journal of Fatigue, 20 (1), 9-34.
10. Halfpenny, A., 1999. Key Engineering Materials, 167, 401-410.
11. Horas, C.S., Correia, J.A.F.O., De Jesus, A.M.P., Calçada, R., Aenlle, M.L., Kripakaran, P., Pelayo, F., Fenandez-Canteli, A., 2016. Application of modal superposition technique in the fatigue analysis using local approaches, Procedia Engineering, 160, 45-52.
12. Marsh G., Wignall., Thies P.R., Barltrop N., Incecik A., Venugopal V., Johanning., 2016. Review and application of Rainflow residue processing techniques for accurate fatigue damage estimation, International Journal of Fatigue, 82 (3), 757-765.
13. Matsuishi M., Endo T., 1968. Fatigue of metals subject to varying stress, Proc. Kyushu Branch of Japan Society of Mechanical Engineers, 37-40.
14. MIL-HDBK-5J, 2003. Metallic Materials And Elements for Aerospace Vehicle Structures, Department of Defense Handbook, U.S.
15. Miner, M.A., 1945. Cumulative damage in fatigue, Journal of Applied Mechanics, 12, 159-164.
16. Mršnik, M., Slavič, J., Boltežar, M., 2016. Frequency-domain methods for a vibration-fatigue-life estimation – Application to real data, International Journal of Fatigue, 47, 8-17.
17. Palmgren, A., 1924, Die lebensdauer von kugellagern, VDI-Zeitschrift, 68, 339-341.
18. Palmieri, M., Česnik, M., Cianetti, F., Slavič., J Boltežar, M., 2017. Non-Gaussianity and non-stationarity in vibration fatigue, International Journal of Fatigue, 97, 9-19.
19. Piersol, G. A., 1964. The Measurement and Interpretation of Ordinary Power Spectra for Vibration Problems, NASA Contractor Report, U.S.
20. Quigley, J., Lee, Y., 2012. Assessing Dirlik's Fatigue Damage Estimation Method for Automotive Applications, SAE International Journal of Passenger Cars – Mechanical Systems, 5(2), 911-920.
21. Sherratt, F., Bishop, N.W.M., Dirlik T., 2005. Predicting fatigue life from frequency domain data, Enginnering Integrity, 8, 12-16.