160m桁架式预应力钢管风电塔塔柱法兰节点抗疲劳性能研究

Fatigue Performance Study on Flange Joints of a 160m High Truss Prestressed Steel Pipe Wind Turbine Tower

在低风速地区,风电机组大型化并提升轮毂高度是获取更高效、稳定风资源的有效手段,桁架式钢管风电塔是一种新型的组合式高风塔,利用钢绞线对塔柱施加预压力以提高塔柱节点抗疲劳性能。分析一2.5MW机组、轮毂高度为160m的桁架式预应力钢管风电塔塔柱法兰连接节点的抗疲劳性能,该节点法兰为锻造高颈法兰,根据有限元分析及疲劳荷载Markov矩阵,采用名义应力法计算法兰螺栓、热点应力法计算法兰颈部对接焊缝焊趾处损伤累计值。分析结果表明锻造高颈法兰高强螺栓及法兰颈部对接焊缝焊趾处应力变化均存在非线性特征;塔柱预压力可降低塔柱在疲劳循环荷载下的平均应力,抑制法兰板张开,提升节点抗疲劳性能。

In areas with low wind speeds large-scale wind turbines and increased hub height are effective means to obtain more efficient and stable wind resources.The latticed wind turbine tower is a new type of combined wind tower which use prestressed steel strands to exert pressure to the tower column to improve the joint fatigue performance.In this paper the fatigue performance of high-neck forged flange joints in a 160-m high prestressed lattice 2.5MW wind turbine tower was analyzed.According to the finite element analysis and the fatigue load Markov matrix the cumulative damage value of the bolts was calculated using the nominal stress method and the cumulative damage value at the toe of the flange neck butt weld was calculated using the hot spot stress method.The analysis results show that the stress change of the high-stress bolts and at the toe of the flange neck butt weld is nonlinear the prestress of tower column can reduce the average stress of the tower column under fatigue cyclic loading restrain the flange plate from opening and improve the fatigue resistance of the joint.