| dc.description.abstract | Energy issue is one of the most important topics in Taiwan, and so is the wind power. The size of wind turbine is getting larger to satisfy the needs of electric energy, but it results in an increment of cost and external loads.
The wind-induced loads and stresses of Vestas V80-2MW wind turbine were analyzed. The author inspected the setting of inflow conditions first, and then investigated the wind-induced loads of the wind turbine under both normal power production and several extreme wind speeds. The influence of wind shear, turbulence intensity, and yaw misalignment were discussed. The results showed that the pitch angle of blade was at 0 position when the projected area of a blade was maximum. The wind-induced loads increased with turbulence intensity, and such increment of loads increased with mean wind speed. The yaw misalignment had an apparent effect on the lateral force acting on the tower. When the wind turbine was under extreme wind speed and parked, e.g., typhoon, the maximum lateral force occurred at 67.5 of yaw misalignment. With respect to the stress analysis of tower, the tower of wind turbine will not fail under normal power production or the specific wind speeds that were required in IEC 61400-1 standard. In modal analysis, the resonance of tower will not occur under normal power production with rated rotor speed. In stress analysis of bolt, the stress at bolt root was very high due to the effect of stress concentration, which resulted in local plastic deformation. The stress at the center of cross-section of bolt was identical to the value that was calculated by empirical formula. | en_US |