Full Content is available to subscribers

Subscribe/Learn More  >

Fatigue Life Assessment of Single Layer 60512 PVDF Barrier in Unbonded Flexible Risers

[+] Author Affiliations
Upul S. Fernando, Michelle Davidson

GE Oil & Gas, Newcastle upon Tyne, UK

Paper No. OMAE2015-41329, pp. V05BT04A013; 8 pages
  • ASME 2015 34th International Conference on Ocean, Offshore and Arctic Engineering
  • Volume 5B: Pipeline and Riser Technology
  • St. John’s, Newfoundland, Canada, May 31–June 5, 2015
  • Conference Sponsors: Ocean, Offshore and Arctic Engineering Division
  • ISBN: 978-0-7918-5652-9
  • Copyright © 2015 by ASME


The polymeric barrier is one of the key components in a flexible pipe, the sound function of which is essential for the containment of the transported medium, ensuring no leakage to the environment which could result in undesired consequences. According to API 17J the barrier design must be able to sustain certain static and dynamic strain conditions however; the actual design or the fatigue assessment of the barrier is not covered within the standard. Since the barrier is subjected to the same dynamic loading as the pipe the durability and integrity of the barrier is a key issue that needs to be addressed during barrier design for dynamic risers. This paper discusses a fatigue life assessment procedure for a barrier made of copolymer Grade 60512 PVDF.

A flexible pipe barrier is manufactured by continuous extrusion of polymer onto a metallic carcass. The carcass has a spiral structure with an irregular outer profile. As such, the extruded polymer on this irregular surface inevitably gives non-uniform thickness and geometric anomalies where the polymer has flowed into gaps in the carcass. During pipe loading such anomalies act as stress concentrations and become critical locations for fatigue crack formation. The evaluation of the effect of the barrier profile shape on the fatigue durability of the barrier is therefore an essential requirement, in particular, in cases where the barrier consists of a single extruded polymer layer.

Within the procedure outlined in this paper, the fatigue assessment of the barrier is made using the local plastic strain behaviour. The maximum stress concentration factor and the acceptable profile for the extruded barrier are selected to provide adequate safety margins for the project specific loading conditions. A procedure has been proposed to predict the local plastic strain of the barrier using global service loading data.

Copyright © 2015 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