High-Fidelity Simulation and Sensitivity Study of Spanwise Stiffness Distribution on Nonlinear Aeroelastic Response of 15 MW Reference Turbine Blades

With the trend towards offshore and larger-scale wind turbines, the increase in blade size makes the trade-off between structural optimization and economic feasibility more critical. To address this issue, this study focuses on the IEA 15 MW offshore wind turbine and investigates the influence of stiffness distribution on its dynamic response, based on the frameworks of multi-body dynamics, the co-rotational beam method, and the free vortex wake method. Results show that blade mid-span stiffness has the most significant influence on system performance. Reducing flapwise bending stiffness increases mean flapwise displacement by 53.8%. This greatly raises the risk of structural damage. Power output is most sensitive to torsional stiffness. Lowering torsional stiffness reduces mean power by 6.9%. This significantly impacts the economic benefits of wind farms. This study contributes to optimizing the structure of large wind turbine blades, enhancing their reliability, and improving cost-effectiveness.