INFLUENCE AND COMPARISON OF VERTICAL AND HORIZONTAL EARTHQUAKE LOADS ON THE CRACK TIP STRAIN FIELD OF A 1.5 MW WIND TURBINE TOWER

Taking a 1.5 MW wind turbine tower with different initial crack lengths as the research object, vertical and horizontal earthquake loads with four earthquake intensities and three actual earthquakes were applied, respectively. The influence of vertical and horizontal earthquake loads on the strain field at the crack tip of the wind turbine tower was studied and compared. The results indicate that both under vertical and horizontal earthquake loads, the equivalen plastic strain area at the crack tip increases with the increase of earthquake intensity, but under horizontal earthquake loads, the equivalent plastic strain area at the crack tip increases more rapidly. Under earthquake intensities of Ⅵ and Ⅶ, the impact of vertical earthquake loads is greater than that of horizontal earthquake loads. As the earthquake intensity increases, the impact of horizontal earthquake loads increases sharply under earthquake intensities of Ⅷ and Ⅸ, and far exceeding the impact of vertical earthquake loads. The impact of vertical actual earthquake load on the crack tip equivalent plastic strain area is related to the magnitude and earthquake acceleration time-history curve, while the impact of horizontal actual earthquake load on the crack tip equivalent plastic strain area is related to the earthquake acceleration time-history curve.