S-N Curve Deduction of a KTX High-Speed Train Structure for an Accelerated Life Testing

가속수명시험을 위한 KTX고속열차 구조물의 S-N 선도 추정

  • 정달우 (한양대학교 대학원 기계공학과) ;
  • 최낙삼 (한양대학교 기계정보경영학부) ;
  • 박수한 ((주) 알에스피)
  • Published : 2009.04.01


An accelerated fatigue test is essentially required to maintain the reliability of the actual structures of KTX under operation conditions. However, actual fatigue life cannot be obtained because the conventional fatigue tests are not adequate to the real load conditions. Moreover foreign component makers have not provided data of the loading stresses (S) versus cycles at the failure (N). In this study, we suggested a deduction method of the S-N curve for establishing an accelerating test under various load levels. Load history was acquired from the field tests. A Rainflow method was used on the cycle counting of the field load data. After that, an S-N curve was obtained through the iteration process under the condition that the damage index satisfies to 1 in the Miner's rule. The deduced S-N curve was applied to the performance evaluation of Korean-made sealed knuckles compared with imports.


Rainflow Counting;Accelerated Life Testing;Miner's Rule;S-N Curve Deduction;Equivalent Stress


  1. Allegri, G. and Zhang, X., 2008, 'On the inverse power laws for accelerated random fatigue testing,' International Journal of Fatigue, Vol. 30, No. 6, pp. 967-977
  2. Yang, J. N. and Jones, D. L., 1980, 'Effect of Load Sequence on the Statical Fatigue of Composite,' AIAA Journal, Vol. 18, No. 12, pp. 1525-1531
  3. Staevski, K. and Chankov, D., 1995, 'A Comparative Analysis of Accelerated Methods for Fatigue Life and Reliability Prediction of Machine Parts under Variable Loading,' Journal of Material Science and Technology, Vol. 3, No. 1, pp. 30-39
  4. Yang, X., Yao, W. and Chen, Y., 2002, 'Application of Accelerated Fatigue tests to Study Calendar Life on Airplane Structure,' Corrosion Science and Protection Technology, Vol. 14, No. 3, pp.172-174
  5. Salzman, R. H. and Reaburn, S. M., 2001, 'Probabilistic Modelling for Timing Belt Fatigue Life Predictions using Accelerated Testing,' International Journal of Materials & Product Technology, Vol. 16, No.4-5, pp. 446-461
  6. Stephens, R. I., Dindingert, P. M. and Gungert, J. E., 1997, 'Fatigue Damage Editing For Accelerated Durability Testing using Strain Range and SWT Parameter Criteria,' International Journal of Fatigue, Vol. 19, No. 8-9, pp. 599-606
  7. Zhang, C., Chuckpaiwong, I., Liang, S. Y. and Seth, B. B., 2002, 'Mechanical Component Lifetime Estimation Based on Accelerated Life Testing With Singularity Extrapolation,' Mechanical Systems and Signal Processing, Vol. 16, No. 4, pp. 705-718
  8. Kim, J. J., Chang, S. W., Son, Y. K., 2008, 'Electrical Lifetime Estimation of a Relay by Accelerated Life Test,' Transactions of KSME A, Vol. 32, No. 5, pp. 430-436
  9. Oh, K. H. and Lee, C. M., 2004, 'Harmonic Generation and System Response Characteristics in Electrified Railway,' Korean Society for Railway, Vol. 7, No. 1, pp.60-64
  10. ASTM, 2002, 'Standard Practices for Cycle counting in Fatigue Analysis,' Annual Book of ASTM Standard, E1049-85, pp. 1-10
  11. Winston, W. L., 2004, 'Microsoft Excel Data Analysis and Business Modeling,' Microsoft press
  12. Kim, Y. J., Choi, J. H., Han, D. C. and Kim, Y. G., 2005, 'The Study on Wheel Wear Analysis in UIC60 and KS50N of Korea High Speed Railway,' Korean Society for Railway, Vol. 2005, No. 0, pp. 1-6
  13. Specifications for construction work, 'Technical Report of Sealed Knuckle,' KORAIL
  14. Lee, K. Y., Park, B. H. and Lee, D. Y., 2003, 'Program Development for the Determination of Equivalent Load for Accelerated Fatigue Testing and the Estimation of Fatigue Life,' Korean Society for Railway, Vol. 6, No. 4, pp. 265-272
  15. Cheng, G. and Plumtree, A. , 1998, 'A Fatigue Damage Accumulation Model Based on Continuum Damage Mechanics and Ductility Exhaustion,' International Journal of Fatigue, Vol. 16, No. 4, pp. 287-293
  16. Nelson, W. B., 2004, 'Applied Life Data Analysis,' John Willey & Sons
  17. Kim, J. C., Jung, H. B., and Lee, J. E., 2003, 'A Study on Prediction of Rouring Noise for Railway,' Journal of KSNVE, Vol. 13, No. 1, pp. 56-62
  18. Chu, S. H., Son, S. H., Ryu, Y. I., Hea, S. J. and Yim, H. J., 2005, 'A Study on Various Factors of Fatigue Analysis for Knuckle,' Korean Society of Automotive Engineers, KSAE05, F0259, pp. 1639-1645

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