The Wind Load Responses And Fatigue Analysis Of Wind Turbine Components

The status of green energy is increasing day by day in national security and development, wind turbine has become the focus of attention of the research community. Since the working environment of wind turbine is poor, random wind loads from all directions, the shape characteristics and the load characteristics determine that the fatigue failure is the main failure mode. The whole life of the wind turbine is determined by the fatigue life of the main components of the wind turbine.So it is of significance to study the response and fatigue analysis of the main components of wind turbine.In this paper, the concept of mean wind and fluctuating wind and its relative properties were introduced and the effect of wind on the structure was studied, the finite element model was established for 1.5MW horizontal axis wind turbine blade,tower and hub, the time history of fluctuating wind speed is obtained by simulation,the wind pressure time history is obtained by wind velocity and wind pressure. The life of the wind turbine was estimated by calculating the response of each component of wind turbine under wind load. The work is as follows:1. The finite element model is established for wind turbine blade in three different positions. According to the formula, the equivalent static wind load of the wind turbine is obtained. Regarding the effect of gravity load and rotational angular velocity, the blade position 1 is chosen to calculate the response under three different load conditions and the results are analyzed.2. Selecting the Loading conditions which considers the influence of gravity load and rotation angle speed, load to the three different positions of the blade. The stress and displacement at three different positions are calculated by using the static analysis function of ANSYS.3. Simulation of fluctuating wind load is conducted by using linear filtering method, the hot spot of the blade is determined by using the static analysis, wind pressure time history is obtained according to the relationship between wind speed and wind pressure conversion, the response of blade under fluctuating wind pressure is calculated by the finite element software ANSYS.4. The concept of fatigue cumulative damage theory and fatigue curve are introduced, The bottom rigid connection, tower model and wheel model with pilefoundation stiffness are established. The Weibull distribution function is used to simulate the distribution of wind speed, and miner linear cumulative damage rule is used to calculate the fatigue life of root of blade airfoil curve on the five hot spot location, tower root and hub.