### Abstract

bending moment time series are generated using a fully coupled aero-hydro-elastic model accounting for non-linear water waves and sea current. The fatigue damage is analysed in terms of the lifetime fatigue damage equivalent bending moment. Three different mean value correction techniques are considered, namely, Goodman, Walker, and mean sensitivity factor. An increase in the lifetime fatigue damage equivalent bending moment between 6% (mean sensitivity factor) and 33% (Goodman) is observed when mean load corrections are considered. The lifetime damage equivalent bending moment is further increased by approximately 7% when considering sea current forces. The results indicate that mean load correction techniques should be employed in the analysis of the fatigue life of offshore wind turbine monopile foundations. Moreover, it is shown that a nonlinear hydrodynamic model is required in order to correctly account for the effect of the current.

Original language | English |
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Title of host publication | Computational Methods in Marine Engineering V - Proceedings of the 5th International Conference on Computational Methods in Marine Engineering, MARINE 2013 |

Editors | B. Brinkmann, P. Wriggers |

Publisher | International Center for Numerical Methods in Engineering |

Publication date | 2013 |

Pages | 818-829 |

ISBN (Print) | 9788494140747 |

Publication status | Published - 2013 |

Event | 5th International Conference on Computational Methods in Marine Engineering - Hamburg, Germany Duration: 29 May 2013 → 31 May 2013 Conference number: 5 |

### Conference

Conference | 5th International Conference on Computational Methods in Marine Engineering |
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Number | 5 |

Country | Germany |

City | Hamburg |

Period | 29/05/2013 → 31/05/2013 |

### Cite this

*Computational Methods in Marine Engineering V - Proceedings of the 5th International Conference on Computational Methods in Marine Engineering, MARINE 2013*(pp. 818-829). International Center for Numerical Methods in Engineering.

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*Computational Methods in Marine Engineering V - Proceedings of the 5th International Conference on Computational Methods in Marine Engineering, MARINE 2013.*International Center for Numerical Methods in Engineering, pp. 818-829, 5th International Conference on Computational Methods in Marine Engineering, Hamburg, Germany, 29/05/2013.

**Mean load effects on the fatigue life of offshore wind turbine monopile foundations.** / Blasques, José Pedro Albergaria Amaral; Natarajan, Anand.

Research output: Chapter in Book/Report/Conference proceeding › Article in proceedings › Research › peer-review

TY - GEN

T1 - Mean load effects on the fatigue life of offshore wind turbine monopile foundations

AU - Blasques, José Pedro Albergaria Amaral

AU - Natarajan, Anand

PY - 2013

Y1 - 2013

N2 - This paper discusses the importance of mean load effects on the estimation of the fatigue damage in offshore wind turbine monopile foundations. The mud linebending moment time series are generated using a fully coupled aero-hydro-elastic model accounting for non-linear water waves and sea current. The fatigue damage is analysed in terms of the lifetime fatigue damage equivalent bending moment. Three different mean value correction techniques are considered, namely, Goodman, Walker, and mean sensitivity factor. An increase in the lifetime fatigue damage equivalent bending moment between 6% (mean sensitivity factor) and 33% (Goodman) is observed when mean load corrections are considered. The lifetime damage equivalent bending moment is further increased by approximately 7% when considering sea current forces. The results indicate that mean load correction techniques should be employed in the analysis of the fatigue life of offshore wind turbine monopile foundations. Moreover, it is shown that a nonlinear hydrodynamic model is required in order to correctly account for the effect of the current.

AB - This paper discusses the importance of mean load effects on the estimation of the fatigue damage in offshore wind turbine monopile foundations. The mud linebending moment time series are generated using a fully coupled aero-hydro-elastic model accounting for non-linear water waves and sea current. The fatigue damage is analysed in terms of the lifetime fatigue damage equivalent bending moment. Three different mean value correction techniques are considered, namely, Goodman, Walker, and mean sensitivity factor. An increase in the lifetime fatigue damage equivalent bending moment between 6% (mean sensitivity factor) and 33% (Goodman) is observed when mean load corrections are considered. The lifetime damage equivalent bending moment is further increased by approximately 7% when considering sea current forces. The results indicate that mean load correction techniques should be employed in the analysis of the fatigue life of offshore wind turbine monopile foundations. Moreover, it is shown that a nonlinear hydrodynamic model is required in order to correctly account for the effect of the current.

M3 - Article in proceedings

SN - 9788494140747

SP - 818

EP - 829

BT - Computational Methods in Marine Engineering V - Proceedings of the 5th International Conference on Computational Methods in Marine Engineering, MARINE 2013

A2 - Brinkmann, B.

A2 - Wriggers, P.

PB - International Center for Numerical Methods in Engineering

ER -