0

Full Content is available to subscribers

Subscribe/Learn More  >

Fatigue Loads on Offshore Wind Turbines Due to Weakly Non-Linear Waves

[+] Author Affiliations
Jenny M. V. Trumars

Chalmers University of Technology, Göteborg, Sweden

Niels Jacob Tarp-Johansen, Thomas Krogh

Riso̸ National Laboratory, Roskilde, Denmark

Paper No. OMAE2005-67064, pp. 483-492; 10 pages
doi:10.1115/OMAE2005-67064
From:
  • ASME 2005 24th International Conference on Offshore Mechanics and Arctic Engineering
  • 24th International Conference on Offshore Mechanics and Arctic Engineering: Volume 2
  • Halkidiki, Greece, June 12–17, 2005
  • Conference Sponsors: Ocean, Offshore and Arctic Engineering Division
  • ISBN: 0-7918-4196-0 | eISBN: 0-7918-3759-9
  • Copyright © 2005 by ASME

abstract

Due to the pronounced dynamic behavior of wind turbines, fatigue load effects may be quite sensitive to the precise modeling of the frequency content of the wave loading. As the offshore wind turbine technology progresses, larger and larger turbines will be placed at still deeper waters, causing the resonant frequency of the first eigen mode of a traditional bottom-fixed support structure to be typically in the range from 0.25 Hz to 0.35 Hz. The deeper the water and the larger the turbine, the lower the frequency will be. As an example, wave measurements from the offshore wind farm Bockstigen show a second peak at approximately 0.3 Hz in the wave spectrum. Thus this peak, or similar peaks realized at shallow water sites, may very well be dynamically amplified in the response. This second peak cannot be modelled with a linear wave model, and a wave model taking non-linearities into account has to be used. In the presented work, both a linear and a non-linear wave model are used to study the fatigue in an offshore wind power plant and the difference is compared. Time series of irregular linear and non-linear waves are calculated, and structural calculations of an offshore wind turbine with a slender support structure are used in the analysis of the fatigue loads. The forces on the structure are calculated using Morison’s equation, integrating along the structure and lumping the loads in nodes for the structural calculations. The difference between the wave models is significant and the non-linear model yields higher fatigue damage than the linear one.

Copyright © 2005 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