Full Content is available to subscribers

Subscribe/Learn More  >

Bending Stiffeners for Extreme and Fatigue Loading of Unbonded Flexible Risers

[+] Author Affiliations
Russell Smith

MCS, Aberdeen, Scotland

Paper No. OMAE2008-57464, pp. 405-413; 9 pages
  • ASME 2008 27th International Conference on Offshore Mechanics and Arctic Engineering
  • Volume 3: Pipeline and Riser Technology; Ocean Space Utilization
  • Estoril, Portugal, June 15–20, 2008
  • Conference Sponsors: Ocean, Offshore and Arctic Engineering Division
  • ISBN: 978-0-7918-4820-3 | eISBN: 0-7918-3821-8
  • Copyright © 2008 by ASME


Bending stiffeners constrain the dynamic radius of flexible risers at offshore platform and subsea interfaces. The extreme bending and fatigue hotspots of a flexible riser occur near these interfaces. Conventional design of bending stiffeners first account for the extreme metocoean environment to ensure the riser does not bend below the minimum allowable bending radius (MBR). The stiffener design for extreme loading normally proves acceptable for less onerous fatigue loading provided the steel armour in riser annulus stays dry. Flexible riser operations have shown that there are several mechanisms for the annulus to loose its dry-state. A flexible riser that is not fatigue tolerant to a non-dry annulus often needs to be replaced at short notice or shut-down due to the rapid onset of corrosion fatigue of the steel armour wires. This paper demonstrates recent advances in designing bending stiffeners so that a flexible riser can sustain life of field operation with a non-dry annulus. These advances are accomplished by optimising the tapered profile of the bending stiffener and accounting for additional stiffening due to bending hysteresis in a flexible riser. A case study is presented to demonstrate the improvement in fatigue performance of a flexible riser.

Copyright © 2008 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