风力发电机组高强度螺栓的疲劳预测

Fatigue prediction of high-strength bolts in wind turbines

风力发电机组法兰盘和叶根轮毂处通过高强度螺栓进行连接,大多数风力发电机塔筒发生倒塌就是连接螺栓疲劳所导致的。为了减少此类塔筒倒塌事故的发生,提出了一种新的螺栓疲劳损伤分析和预测方法。针对2.0 MW风力发电机组的高强度连接螺栓,采用超声探头和温度传感器采集螺栓数据,获得螺栓随机应力谱;然后基于雨流计数法和Goodman公式修正应力谱,提取应力循环数据;最后基于螺栓材料S-N曲线和Miner线性累计损伤理论,构建螺栓疲劳预测模型。实验结果表明,所估算的螺栓疲劳损伤远小于螺栓疲劳极限,满足风力发电机组的设计寿命要求。

The flange plate and blade root hub of wind turbines are connected by high-strength bolts,and the collapse of most wind turbine towers is caused by the fatigue of the connecting bolts.In order to reduce the occurrence of such tower collapse accidents,a new method for analyzing and predicting bolt fatigue damage is proposed.For high-strength connecting bolts of 2.0 MW wind turbine generators,ultrasonic probes and temperature sensors are used to collect bolt data and obtain random stress spectra of the bolts.Then the stress spectrum is modified based on the rain flow counting method and Goodman formula,and the stress cycle data are extracted.Finally,based on the S-N curve of bolt material and Miner's linear cumulative damage theory,a bolt fatigue prediction model is constructed.The experimental results show that the estimated bolt fatigue damage is far less than the bolt fatigue limit,which meets the design life requirements of the wind turbine.