Multiaxial fatigue analysis on the IEA 3.4 MW wind turbine for floating offshore application

Designing wind turbine blades for offshore applications presents significant structural challenges due to their flexibility and exposure to varying loads. However, the existing literature often overlooks the impact of fatigue on the blade composites. This study aims to investigate the influence of blade flexibility on multiaxial fatigue analysis for offshore wind turbine applications. To achieve this objective, a comprehensive analysis of the IEA 3.4 MW reference wind turbine is performed, considering both fixed and floating configurations. First, an overview of offshore wind energy and fatigue theory is conducted. Then, an aeroelastic analysis of the wind turbine blade, incorporating realistic environmental load simulations, is developed. After that, multiaxial fatigue assessment techniques are em??ployed to predict the expected blade lifetime and evaluate the damage equivalent load along the entire length of the blade. Additionally, the critical wind speed conditions that could lead to fatigue failure for both fixed and floating configurations are investigated. The research findings indicate that the fixed configuration demonstrates a longer predicted service life compared to the floating configuration. Through multiaxial fatigue analysis on the IEA 3.4 MW reference wind turbine blade, this study enhances the understanding of the turbine’s structural integrity and reliability. These results have significant implications for the wind energy industry, as they contribute to a more thorough understanding of the structural behavior of wind turbine blades under multiaxial fatigue conditions. By addressing the impact of blade flexibility on fatigue life, it is possible to improve the design and maintenance strategies, leading to improved performance and cost-effectiveness of offshore wind energy systems.