高水头抽水蓄能机组顶盖螺栓动应力测试及疲劳研究

Research on Dynamic Stress Testing and Fatigue of Head Cover Bolt in High Head Pumped Storage Unit

在水泵水轮机运行过程中,由于振动传递,顶盖螺栓承受循环的交变应力,其可能会发生疲劳断裂的情况,这是由螺栓所受动应力引起的。依托某高水头抽水蓄能电站项目,结合水泵水轮机结构设计及现场运行情况,对顶盖螺栓在不同工况下的动应力进行测试。使用有限元分析软件全面分析螺栓动应力,再基于疲劳累积损伤理论,采用雨流计数法统计计算结果,并结合螺栓的S-N曲线,进行基于动应力的疲劳损伤分析,得到顶盖螺栓的疲劳损伤。

During the operation of the water pump turbine,due to vibration transmission,the top cover bolts are subjected to cyclic alternating stress,which may result in fatigue fracture caused by the dynamic stress on the bolts.Based on a high head pumped storage power station project,combined with the structural design and on-site operation of the pump turbine,the dynamic stress of the top cover bolts under different working conditions was tested.Finite element analysis software was used to comprehensively analyze the dynamic stress of the bolts.Then,based on the theory of fatigue cumulative damage,the rainflow counting method was used to statistically calculate the results.Combined with the S-N curve of the bolts,fatigue damage analysis based on dynamic stress was carried out to obtain the fatigue damage of the top cover bolts.