Abstract: In order to obtain the dynamic response of the blade of horizontal axis wind turbines subjected to the time-varying load, the blade is treated as a cantilever and discretely modeled by applying two-node beam element. To consider the rotating effect of the blade, the centrifugal stiffening and aerodynamic damping are taken into account. Then the natural dynamic characteristics of the bending vibration of the blade are analyzed. Through establishing the structural dynamic equation and calculating the time-varying load acting on the blade, the dynamic response of the blade is calculated by applying Newmark method and modal superposition principle. A corresponding finite element calculation program is developed to carry out the numerical analysis. The power production load case of a 1.0 MW wind turbine operating in turbulent wind field is simulated by applying the developed program. The simulation results indicate that the blade of the large-scale horizontal axis wind turbine undergoes significant vibration and deformation during operation, and the centrifugal stiffening and aerodynamic damping both considerably affect the dynamic response of the blade.

Key words: Aerodynamic damping, Blade, Centrifugal stiffening, Dynamic response, Wind turbine