Fatigue Strength Assessment of TLP Tendon Porch Using API 2W Gr.50 Steel

  • Im, Sung-Woo (Research Institute of Steel Technology) ;
  • Seo, Young-Seok (School of Naval Architecture & Ocean Engineering, University of Ulsan) ;
  • Lee, Joo-Sung (School of Naval Architecture & Ocean Engineering, University of Ulsan)
  • Published : 2007.03.31

Abstract

This paper is concerned with the fatigue strength assessment of tendon porch found which is categorized as the special structural member in TLP. Large-scale tendon porch specimens have been designed and fabricated with API 2W Gr.50 steel recently produced by POSCO. Fatigue test has been carried out for three tendon porch specimens under various load level. Fatigue strength has been evaluated based on the nominal stress range and the results are compared with the fatigue design curve of DnV RP-C203. From the present experimental study, it has been found that the porch specimens satisfy the fatigue design rule although test was carried out under the positive stress ratio. It can be, therefore, said that the API 2W steel produced by POSCO possess sufficient fatigue strength.

Keywords

References

  1. Im, S.W., I.H. Chang, K.K. Park, C.H. Jo and K.Y. Kim. 2005a. A Study on the Fatigue Crack in Large-Scale Tubular Joints for Offshore Structures, Proceedings of 5th ISOPE Conference, 341-345
  2. Im, S.W., I.H. Chang, C.R. Jo and K.K. Park. 2005b. Fatigue Behavior of Large Scale Tubular Joint for API 2W Gr.50 Steel, Journal of Ocean Engineering & Technology, 19,3, 54-58
  3. Im, S.W. 2005. A Prospective of Offshore Structure and Fatigue Tests of Large-Scale Structures, Proceedings of 14th Steel Usage Technology Conference, POSCO, 221-232
  4. Pytel, A. and J. Kiusalaas. 2003. Mechanics of Materials, Brooks/Cole-Thomson Learning, Inc
  5. Cook, R.D., D.S. Malkus, M.E. Plesha and R.J. Witt. 2002. Concepts and Applications of Finite Element Analysis, 4th edition, John Wiley & Sons, Inc
  6. DnV OS-C103. 2001. Structural Design of TLPs
  7. DnV RP-C203. 2001. Fatigue Strength Analysis of Offshore Steel Structures