MW级风电机组T型法兰地锚螺栓疲劳强度计算

The fatigue strength calculation of T-flange anchor bolts for MW wind turbines

针对某风场MW级风电机组塔架与基础连接强度不足的问题,将L型法兰与基础环连接更改为T型法兰与混凝土地基连接,并对该连接进行了疲劳强度校核。首先基于Petersen方法和VDI2230规范对T型法兰连接进行力学模型简化,得到地锚螺栓与地基的等效刚度;然后基于Petersen方法得到外载荷与地锚螺栓受力之间的函数关系,并利用该关系将疲劳外载荷转化为地锚螺栓的疲劳应力谱;最后结合疲劳载荷循环次数及地锚螺栓S-N曲线得到地锚螺栓的疲劳损伤值,实现对地锚螺栓的疲劳强度评估。分析结果表明,T型法兰地锚螺栓疲劳强度满足设计要求。

Aiming at the insufficient fatigue strength of the L-flange connection between the tower and the foundation in the MW wind turbine,it improves the L-flange connection to the T-flange connection to the concrete foundation,and analyzes the fatigue strength.Based on the Petersen method and the VDI 2230 specification,it simplifies the mechanical model of the connection of the T-flange anchor bolt and the foundation,obtains the equivalent stiffness of the anchor bolt and the foundation,builds the function relationship between the external load and the anchor bolt force based on the Petersen method.Then,it transforms the fatigue load spectrum into the fatigue stress spectrum of the anchor bolt,combines the fatigue load cycle number with the S-N curve of the anchor bolt to calculate the fatigue damage of the anchor bolt.The results show that the fatigue strength of the T-flange anchor bolt can meet the design requirement.