Long-term fatigue damage sensitivity to wave directionality in extra-large monopile foundations. (February 2018)

• Record Type: Journal Article
• Authors: Horn, Jan-Tore; Krokstad, Jørgen R; Amdahl, Jørgen
• Other Names: Ringsberg JW guest-editor.
• Is Part Of: Proceedings of the Institution of Mechanical Engineers. Volume 232:Number 1(2018:Feb.)
• Page Start: 37
• Page End: 49
• Publication Date: 2018-02
• Subjects: Directionality -- fatigue -- hydrodynamics -- long-term statistics -- offshore environment -- offshore wind turbines -- swell; Marine engineering -- Periodicals; 623.805
• DOI: 10.1177/1475090217727136
• Languages: English
• ISSNs: 1475-0902

Abstract

The fatigue damage sensitivity to wave directionality on large-diameter monopile foundations for use in the offshore wind turbine industry is investigated. A frequency-domain approach with the Dirlik method is used to estimate fatigue damage and to evaluate the effect of wave spreading and swell separation compared to a total sea representation. To evaluate the long-term impact, 30 years of hindcast data from the Dogger Bank area are used. Furthermore, a computationally efficient time-domain model of a 10-MW offshore wind turbine is used to compare with the frequency-domain results. Results show that benefits in terms of structural fatigue can be obtained with directional considerations.