Rain Erosion Modelling of Offshore Floating Wind Turbine Blade Coatings for Fatigue Lifetime Prediction

Wind energy is a key pillar of the global transition to net-zero, with offshore floating wind turbines (OFWTs) offering vast untapped potential. However, OFWT blades are continuously exposed to rain, hail, and airborne particles, causing the protective coating erosion that reduces aerodynamic efficiency, accelerates structure failure, and increases maintenance costs. Addressing this challenge is essential for reliable and cost-effective wind energy production. This project will combine advanced characterisation tests with high-fidelity numerical modelling to predict fatigue lifetime of OFWT blade coatings under harsh marine conditions. Multiple and random droplet impact tests will be conducted to investigate the fatigue failure mechanisms of the novel self-healing polyurethane coating materials. State-of-the-art modelling only captures the elastic behaviour of the protective coating. A cutting-edge fluid-structure interaction framework, based on the Arbitrary Lagrangian-Eulerian-Lagrangian (ALE-L) method, will simulate repeated droplet-coating interactions. A refined viscoelastic-viscoplastic non-local fatigue damage constitutive model will be introduced for the coating phase and calibrated against physical experimental data. Chemical-diffusive controlled self-healing mechanisms will be developed to retrieve the mechanical properties once the coating is damaged. The comprehensive numerical model will be applied to quantify erosion damage growth and predict lifetime. Finally, a practical erosion assessment tool will be created by correlating damage rate with rainfall characteristics to inform operational decision-making systems. Project outcomes will directly support next-generation OFWT blade development by reducing design iterations, preventing premature failures, and lowering lifecycle costs. This work aligns with the United Nations Sustainable Development Goals (Climate Action) and the European Green Deal, advancing a scalable, climate-neutral energy future.