Numerical and Experimental Investigation of Wave Loading on a Monopile Support Structure of Offshore Wind Turbine

2022 ◽  
pp. 342-349
Author(s):  
Linh Cao Luong ◽  
Tri Mai
Keyword(s):  
Experimental Investigation ◽  
Wind Turbine ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Wave Loading ◽  
Support Structure

Design Drivers for Offshore Wind Turbine Jacket Support Structures

2011 ◽  
Author(s):  
Andrew Cordle ◽  
Graeme McCann ◽  
Wybren de Vries
Keyword(s):  
Wind Turbine ◽  
Software Tool ◽  
Structure Design ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Relative Importance ◽  
Wave Loading ◽  
Support Structure ◽  
Design Load ◽  
External Conditions

For the purposes of offshore wind turbine support structure design it is important to understand the relative importance of the various external conditions applied to the structure in the design process. This paper presents results from integrated load calculations performed for an offshore wind turbine on a jacket support structure subject to combined wind and wave loading. A sensitivity analysis is performed on a number of design load case parameters for both fatigue and extreme conditions. Damage equivalent loads and ULS loads are derived using the GH Bladed software tool at a number of key locations on the jacket. Conclusions are drawn regarding the influence of these parameters from comparisons with the baseline load set.

Monitoring Changes in the Soil and Foundation Characteristics of an Offshore Wind Turbine Using Automated Operational Modal Analysis

2013 ◽  
Vol 569-570 ◽  
pp. 652-659 ◽  
Author(s):  
Gert de Sitter ◽  
Wout Weitjens ◽  
Mahmoud El-Kafafy ◽  
Christof Devriendt
Keyword(s):  
Wind Turbine ◽  
Modal Analysis ◽  
Continuous Monitoring ◽  
Low Frequency ◽  
Operational Modal Analysis ◽  
Human Interaction ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Support Structure ◽  
Lower Natural Frequency

This paper will show the first results of a long term monitoring campaign on an offshore wind turbine in the Belgian North Sea. It will focus on the vibration levels and resonant frequencies of the fundamental modes of the support structure. These parameters will be crucial to minimize O&M costs and to extend the lifetime of offshore wind turbine structures. For monopile foundations for example, scouring and reduction in foundation integrity over time are especially problematic because they reduce the fundamental structural resonance of the support structure, aligning that resonance frequency more closely to the lower frequencies. Since both the broadband wave energy and the rotating frequency of the turbine are contained in this low frequency band, the lower natural frequency can create resonant behavior increasing fatigue damage. Continuous monitoring of the effect of scour on the dynamics of the wind turbine will help to optimize the maintenance activities on the scour protection system. To allow a proper continuous monitoring during operation, reliable state-of-the-art operational modal analysis techniques should be used and these are presented in this paper. The methods are also automated, so that no human-interaction is required and the system can track the natural frequencies and damping ratios in a reliable manner.

Key Contributors to Lifetime Accumulated Fatigue Damage in an Offshore Wind Turbine Support Structure

2017 ◽  
Author(s):  
Emil Smilden ◽  
Erin E. Bachynski ◽  
Asgeir J. Sørensen
Keyword(s):  
Wind Turbine ◽  
Fatigue Damage ◽  
Control Strategies ◽  
Time Domain Analysis ◽  
Offshore Wind ◽  
Offshore Wind Turbine ◽  
Wave Loads ◽  
Support Structure ◽  
Wear And Tear ◽  
Collateral Effects

A simulation study is performed to identify the key contributors to lifetime accumulated fatigue damage in the support-structure of a 10 MW offshore wind turbine placed on a monopile foundation in 30 m water depth. The relative contributions to fatigue damage from wind loads, wave loads, and wind/wave misalignment are investigated through time-domain analysis combined with long-term variations in environmental conditions. Results show that wave loads are the dominating cause of fatigue damage in the support structure, and that environmental condtions associated with misalignment angle > 45° are insignificant with regard to the lifetime accumulated fatigue damage. Further, the results are used to investigate the potential of event-based use of control strategies developed to reduce fatigue loads through active load mitigation. Investigations show that a large reduction in lifetime accumulated fatigue damage is possible, enabling load mitigation only in certain situations, thus limiting collateral effects such as increased power fluctuations, and wear and tear of pitch actuators and drive-train components.

Sign in / Sign up

Export Citation Format

Share Document