关键词: 叶根连接, 预埋螺栓套, 连接螺栓, 疲劳强度, 复合材料

Abstract: Fatigue fracture is the main failure mode of the root connection bolts of wind power blades. Based on the analysis data of "Influence on Bolts of Wind Turbine Blade Root Bushing Connection by Connection Parameters", the influence of another 2 parameters to the fatigue life of bushing connection bolts is analyzed, i.e., the thickness of pitch bearing and the outer diameter of bushings. Based on the analysis data, the effects of 6 typical parameters on the fatigue strength of blade root connection bolts are studied and compared. The analysis results show that: (1) increasing the thickness of pitch bearing and increasing the outer diameter of bushings are the most effective methods to improve the fatigue life of the connection bolts. (2) From the perspective of weight reduction, in order to improve the fatigue life of the connection bolt, priority should be given to reducing the shaft diameter and increasing the pretension force the bolts. If it is still not satisfied, increasing the outer diameter of bushings, increasing the flange thickness and increasing the thickness of pitch bearing should be considered successively.

Key words: blade root, bushing connection, connection bolt, fatigue strength, composites