Ocean Systems Engineering

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Free spans monitoring of subsea pipelines

  • Elshafey, Ahmed A. (Faculty of Engineering, Memorial University of Newfoundland) ;
  • Haddara, M.R. (Faculty of Engineering, Memorial University of Newfoundland) ;
  • Marzouk, H. (Faculty of Engineering, Architecture and Science, Ryerson University)
  • Received : 2010.11.23
  • Accepted : 2011.03.11
  • Published : 2011.03.25
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Abstract

The objective of this work is to investigate the possibility of using the longitudinal strain on the surface of a pipe to determine the inception of dangerous free spanning. The long term objective is to develop an online monitoring technique to detect the development of dangerous free spanning in subsea pipelines. This work involves experimental study as well as finite element modeling. In the experiments, the strains at four points on a cross section of a pipeline inside the free span zone are measured. Pipes with different boundary conditions and different diameter to length ratios were tested. The pipe is treated as a simple beam with fixed-fixed or simply supported boundary conditions. The variation of the strains as a function of the diameter to length ratio gives a pointer to the inception of dangerous free spanning. The finite element results agree qualitatively with the experiments. The quantitative discrepancy is a result of the difficulty to replicate the exact boundary conditions that is used by the finite element program.

Keywords

References

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