多工况下风电齿轮箱联接螺栓疲劳寿命分析

Fatigue Life Analysis of the Bolt Connections for Wind Turbine Gearbox under Multiple Working Conditions

针对风电齿轮箱联接螺栓疲劳受载复杂性问题,建立含螺栓的风电齿轮箱有限元模型,分析不同扭转和弯曲载荷下螺栓应力变化规律,依据风力发电机实际载荷谱,分段插值获得螺栓疲劳应力谱;基于雨流计数方法和Palmgrem-Miner疲劳累积损伤理论,结合螺栓材料S-N曲线,预测各疲劳应力谱下螺栓疲劳损伤,研究风电齿轮箱三种疲劳工况下各不同联接螺栓的疲劳寿命。结果表明:各疲劳工况下,前箱体与一级内齿圈间联接螺栓疲劳损伤值较大,疲劳弯矩工况下达最大损伤值0.853;疲劳扭矩工况下螺栓应力随扭矩增大而增大,危险螺栓靠近箱体两侧支撑处;疲劳弯矩工况下箱体产生倾覆效应,M Y弯矩下危险螺栓位于箱体上下两侧,M Z弯矩下危险螺栓位于箱体左右两侧。此次研究工作对提高风电齿轮箱整体使用寿命具有重要意义。

In order to assess the fatigue strength of bolt joint in wind turbine gearbox suffering from complex loads,a finite element model of wind turbine gearbox with bolts was established to analyze the variation law of bolt stress under different torsional and bending loads.On the basis of the actual load spectrum of the wind turbine,the piecewise interpolation method was used to obtain the fatigue stress spectrum of bolt.Based on the rain flow counting method and the Palmgrem-Miner fatigue cumulative damage rule,the fatigue damage of bolt under each fatigue stress spectrum was predicted combined with the S-N curve of bolt′s material,and the fatigue life of different bolt joints in various positions of the wind turbine gearbox was researched.The results show that the fatigue damage value of connecting bolts between the front box and the first level ring gear is larger under each fatigue condition,and the maximum damage value is 0.853 under the fatigue bending condition;the bolt stress increases with the increase of torque under the fatigue torque condition,and the dangerous bolts are located at the fixed position on both sides of the gearbox;while under the bending fatigue moment conditions,the box has an overturning effect,the dangerous bolts under M Y bending moment are located on the upper and lower sides of the box,and the dangerous bolts under M Z bending moment are located on the left and right sides of the box.The research in this paper is of great significance to improve the overall service life of the wind power gearbox.