Full Content is available to subscribers

Subscribe/Learn More  >

Estimation of Extreme Response and Fatigue Damage for Colliding Risers

[+] Author Affiliations
Bernt J. Leira

Norwegian University of Science and Technology, Trondheim, Norway

Tore Holmås

SINTEF, Trondheim, Norway

Kjell Herfjord

Norsk Hydro Research Centre, Bergen, Norway

Paper No. OMAE2002-28435, pp. 433-439; 7 pages
  • ASME 2002 21st International Conference on Offshore Mechanics and Arctic Engineering
  • 21st International Conference on Offshore Mechanics and Arctic Engineering, Volume 2
  • Oslo, Norway, June 23–28, 2002
  • Conference Sponsors: Ocean, Offshore, and Arctic Engineering Division
  • ISBN: 0-7918-3612-6 | eISBN: 0-7918-3599-5
  • Copyright © 2002 by ASME


For design of deep-water riser arrays, consideration must be made of the possibility for mechanical contact between the different riser pipes. Both the anticipated frequency of collision and the resulting stresses in the pipes need to be estimated. Such an assessment need to cover a certain range of conditions regarding environmental loading and surface floater motions. The present paper outlines a procedure which admits the most “critical” conditions to be identified based on an iterative approach. For each “load case”, which corresponds to a certain combination of environmental actions and surface floater motion, the corresponding contact stresses are computed. Furthermore, the accumulated damage for each load case (referred to a certain duration) is estimated. The numerical procedure for external load calculation is based on Computational Fluid Dynamics (CFD). For a given riser spacing, interpolation is performed during the response simulation in a pre-established data base. Contact between pipes is checked at each time step by looping through the nodal coordinates of the Finite Element Mesh which represents the pipe geometry. By assembling the response and accumulated damage which correspond to all the different load cases, the long-term probability distributions and weighted damage can be calculated. The procedure is applied to a particular example riser configuration. The effect of varying current direction (relative to the symmetry axis of the floater and riser configuration) on fatigue damage is focused upon in particular.

Copyright © 2002 by ASME



Interactive Graphics


Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature

Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal

Citing articles are presented as examples only. In non-demo SCM6 implementation, integration with CrossRef’s "Cited By" API will populate this tab (http://www.crossref.org/citedby.html).

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In