A Time-Domain Approach for Aerodynamic Mass and Damping of Wind Turbine Blades

Wind turbines exhibit pronounced dynamic responses under complex environmental loading conditions such as wind, waves, and earthquakes. To this end, this study proposes a decoupled aeroelastic analysis method that explicitly accounts for blade dynamic effects. First, high-fidelity CFD-based forced vibration simulations are conducted to identify frequency-dependent aerodynamic added mass and damping distributed along the blade span. Based on these results, an aerodynamic parameter database is established for four turbine configurations (NREL 5 MW, DTUC10 MW, IEA 15 MW, and IEA 22 MW). Second, a multilayer feedforward neural network surrogate model is developed using this database to predict aerodynamic parameters under varying operating conditions. Next, rational function approximation is employed to transform the frequency-domain aerodynamic transfer function into a low-order time-domain state-space representation. The resulting model is implemented in ABAQUS through user-defined elements, enabling the aerodynamic effects to be incorporated directly into structural dynamic analysis. Finally, the proposed decoupled aeroelastic framework is validated against fully coupled simulations under steady wind, turbulent wind, and combined wind–earthquake loading conditions for 5 MW and 15 MW wind turbines. The results demonstrate that the proposed framework can reproduce the major dynamic responses of the fully coupled model while substantially reducing the computational cost.