International Journal of Naval Architecture and Ocean Engineering

The Society of Naval Architects of Korea (대한조선학회)
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Low-cycle fatigue evaluation for girth-welded pipes based on the structural strain method considering cyclic material behavior

  • Lee, Jin-Ho (Department of Naval Architecture and Ocean Engineering, Pusan National University) ;
  • Dong, Pingsha (Department of Naval Architecture and Marine Engineering, University of Michigan) ;
  • Kim, Myung-Hyun (Department of Naval Architecture and Ocean Engineering, Pusan National University)
  • Received : 2020.03.12
  • Accepted : 2020.08.29
  • Published : 2020.12.31
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Abstract

One of the main concerns in the structural integrity of offshore pipelines is mechanical damage from external loads. Pipelines are exposed to fatigue failure in welded joints due to geometric discontinuity. In addition, fatigue loads such as currents, waves, and platform motions may cause significant plastic deformation and fracture or leakage within a relatively low-cycle regime. The 2007 ASME Div. 2 Code adopts the master S―N curve for the fatigue evaluation of welded joints based on the mesh-insensitive structural stress. An extension to the master S―N curve was introduced to evaluate the low-cycle fatigue strength. This structural strain method uses the tensile properties of the material. However, the monotonic tensile properties have limitations in describing the material behavior above the elastic range because most engineering materials exhibit hardening or softening behavior under cyclic loads. The goal of this study is to extend the cyclic stress-strain behavior to the structural strain method. To this end, structural strain-based procedure was established while considering the cyclic stress-strain behavior and compared to the structural strain method with monotonic tensile properties. Finally, the improved prediction method was validated using fatigue test data from full-scale girth-welded pipes.

Keywords

Acknowledgement

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) through GCRC-SOP (No. 2011e0030013). This work was also supported by the National Research Foundation of Korea (NRF) grant, which is also funded by the Korea government (MOE) (NRF-2017R1D1A1B03035811).

References

  1. American Society of Mechanical Engineers, 2007. ASME Boiler and Pressure Vessel Code, Sec VIII, Div. 2 (ASME BPVC-VIII-22007). New York. USA.
  2. Chris, Hinnant, Paulin, Tony, 2008. Experimental Evaluation of the Markl Fatigue Methods and ASME Piping Stress Intensification Factors. ASME 2008 Pressure Vessels And Piping Conference. American Society of Mechanical Engineers.
  3. Dong, P., 2001. A structural stress definition and numerical implementation for fatigue analysis of welded joints. Int. J. Fatig. 865-876. https://doi.org/10.1016/S0142-1123(01)00055-X.
  4. Dong, P., Hong, J.K., Cao, Z., 2003. Stresses and stress intensities at notches: 'anomalous crack growth' revisited. Int. J. Fatig. 25 (9), 811-825. https://doi.org/10.1016/S0142-1123(03)00130-0.
  5. Dong, P., Hong, J.K., De Jesus, A.M.P., 2007. Analysis of recent fatigue data using the structural stress procedure in ASME Div 2 rewrite. J. Pressure Vessel Technol. 129 (3), 355-362. https://doi.org/10.1115/1.2748818.
  6. Dong, P., Pei, X., Xing, S., Kim, M., 2014. A structural strain method for low-cycle fatigue evaluation of welded components. Int. J. Pres. Ves. Pip. 39-51. https://doi.org/10.1016/j.ijpvp.2014.03.003.
  7. Dowling, Norman E., 2013. Mechanical Behavior of Materials, fourth ed. Pearson, England.
  8. Lee, J.H., Kim, M.H., 2018. Low cycle fatigue evaluation considering the cyclic stressstrain curve of girth-welded pipe based on structural strain method. KWJS.
  9. Markl, A.R.C., 1947. Fatigue tests of welding elbows and comparable double-mitre bends. Trans. ASME 69 (8), 869-879.
  10. Markl, A.R.C., Louisville, K.Y., 1952. Fatigue tests of piping components. Trans. ASME 74, 287-303, 3.
  11. Melvin, J. Maron, Lopez, Robert J., 1991. Numerical Analysis: a Practical Approach, third ed. Wadsworth Pub, Belmont, Calif.
  12. Olusegun, Fatoba, Robert, Akid, 2014. Low cycle fatigue behavior of API 5L X65 pipeline steel at room temperature. Procedia Engineering 279-286. https://doi.org/10.1016/j.proeng.2014.06.263.
  13. Pei, X., Dong, P., 2019. An analytically formulated structural strain method for fatigue evaluation of welded components incorporating nonlinear hardening effects. Fatigue Fract Eng M 42, 239-255. https://doi.org/10.1111/ffe.12900.
  14. Pei, X., Wang, W., Dong, P., 2017. An analytical-based structural strain method for low cycle fatigue evaluation of girth-welded pipes. In: Proceedings of the ASME Pressure Vessels and Piping Conference. https://doi.org/10.1115/PVP2017-66006.
  15. Pei, X., Dong, P., Xing, S., 2019. A structural strain parameter for a unified treatment of fatigue behaviors of welded components. Int. J. Fatig. 444-460. https://doi.org/10.1016/j.ijfatigue.2019.03.010.
  16. Scavuzzo, R.J., Srivatsan, T.S., Lam, P.C., 1998. Fatigue of butt-welded pipe. WRC Bull. 433.