21 Jul 2023
 | 21 Jul 2023
Status: a revised version of this preprint is currently under review for the journal WES.

Quantifying the effect of low-frequency fatigue dynamics on offshore wind turbine foundations: a comparative study

Negin Sadeghi, Pietro D’Antuono, Nymfa Noppe, Koen Robbelein, Wout Weijtjens, and Christof Devriendt

Abstract. Offshore wind turbine support structures are fatigue-driven designs subjected to a wide variety of cyclic loads from wind, waves, and turbine controls. While most wind turbine loads and metocean data are collected at short-term 10-minute intervals, some of the largest fatigue cycles have periods over one day. Therefore, these low-frequency fatigue dynamics (LFFD) are not fully considered when working with the industry-standard short-term window. To recover these LFFDs in the state-of-the-industry practices, the authors implemented a short-to-long-term factor applied to the accumulated short-term damages, while maintaining the ability to work with the 10-minute data. In the current work, we study the LFFD impact on the damage from the Fore-Aft and Side-Side bending moments and the sensors' strain measurements and their variability within and across wind farms. For an S-N curve slope of m=5, up to 65 % of damage is directly related to LFFD.

Negin Sadeghi et al.

Status: final response (author comments only)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on wes-2023-77', Anonymous Referee #1, 13 Aug 2023
    • AC1: 'Reply on RC1', Negin Sadeghi, 18 Aug 2023
  • RC2: 'Comment on wes-2023-77', Anonymous Referee #2, 28 Aug 2023
    • AC2: 'Reply on RC2', Negin Sadeghi, 22 Sep 2023

Negin Sadeghi et al.

Negin Sadeghi et al.


Total article views: 488 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
374 96 18 488 9 9
  • HTML: 374
  • PDF: 96
  • XML: 18
  • Total: 488
  • BibTeX: 9
  • EndNote: 9
Views and downloads (calculated since 21 Jul 2023)
Cumulative views and downloads (calculated since 21 Jul 2023)

Viewed (geographical distribution)

Total article views: 468 (including HTML, PDF, and XML) Thereof 468 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
Latest update: 22 Sep 2023
Short summary
Long-term fatigue damage of four offshore wind turbines using three years of measurement data was performed to have an in-depth study on low-frequency fatigue damage (LFFD) impact on overall consumed life, for the first time. LFFD factor depends on the (linear) SN curve slope, heading, signal and turbine type. Up to ~65 % of the total damage can be related to LFFD. Therefore, the LFFD effect has a significant impact on the final damage.