0

Full Content is available to subscribers

Subscribe/Learn More  >

Friction, Contact Pressure and Non-Linear Behavior of Steel Tubes in Subsea Umbilicals

[+] Author Affiliations
Farzan Parsinejad, Chris Kassner

Chevron Energy Technology Company, Houston, TX

Mark Kurtz

Chevron Upstream and Gas, Houston, TX

Naiquan Ye

Marintek, Trondheim, Norway

Paper No. OMAE2013-10056, pp. V04AT04A004; 9 pages
doi:10.1115/OMAE2013-10056
From:
  • ASME 2013 32nd International Conference on Ocean, Offshore and Arctic Engineering
  • Volume 4A: Pipeline and Riser Technology
  • Nantes, France, June 9–14, 2013
  • Conference Sponsors: Ocean, Offshore and Arctic Engineering Division
  • ISBN: 978-0-7918-5536-2
  • Copyright © 2013 by ASME

abstract

Steel tube umbilical risers in deep water applications are subject to significant variable environmental loads during operation. These tubes are designed to carry high pressure fluids, up to 15,000 psi. The stresses accumulated in the walls consist of contribution from movement of the floating platform on which the umbilical is connected, axial tension due to the weight of umbilical and ancillaries, and internal pressure due to end cap effect.

The helically wound steel tubes in umbilicals are un-bonded and can slip against adjacent layers. Therefore the stresses in these tubes experience a hysterical feature when the slip changes directions. It is known that in addition to bending stress, friction stress range has a major contribution in fatigue damage. If there is full slip, the friction stress range will be a constant value regardless of the load variation. However in many cycles the full slip is not reached and the stress range is proportional to load variation.

This paper focuses on evaluating the impact of friction and contact pressure on helical steel tubes. The initial gaps between steel tubes and adjacent layers, friction coefficients and the contact stiffness are the main factors that affect such investigation. A novel methodology by using UFLEX2D (a MARINTEK product) has been applied for modeling complex umbilical cross sections and for the study of these parameters.

Two cross sections for the same subsea application but with different designs have been investigated in the study. It has been shown how fatigue damage can be significantly impacted by different cross sectional design.

For this study, non-linear moment/curvature relationship has been included in the analyses. Based on the findings of this study, more realistic results can be achieved by including the non-linear behavior in global analysis for fatigue damage calculations instead of using nominal bending stiffness supplied by umbilical manufacturer.

Copyright © 2013 by ASME

Figures

Tables

Interactive Graphics

Video

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

NOTE:
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