风电关键部件连接螺栓液压拉伸器预紧轴力回弹分析  

Analysis of Pretension Reduction of Axial Force of Hydraulic Tensioner for Connecting Bolt of Key Components of Wind Turbine

作　　者：尹国庆 马奔奔 唐林 刘贵林 龚学进 王宇 李源 Yin Guoqing;Ma Benben;Tang Lin;Liu Guilin;Gong Xuejin;Wang Yu;Li Yuan

机构地区：[1]东方电气风电股份有限公司,四川德阳618000

出　　处：《中国重型装备》2023年第3期46-49,70,共5页CHINA HEAVY EQUIPMENT

摘　　要：风力发电机组关键部件的连接螺栓常采用液压拉伸器张拉的方式来预紧,以此来保证螺栓轴力的预紧精度。但是,在张拉前后因为被紧固件结构刚度的变化会造成螺栓有回弹的现象,轴力有所下降。为此建立了液压拉伸器张拉螺栓整个流程的仿真分析方法,模拟了拉伸螺栓、拧紧螺母以及撤离拉伸器的过程,分析了拉伸-预紧-回弹过程中螺栓轴向应力的变化,并考虑了接触面粗糙度对螺栓回弹的影响。通过某型号变桨轴承轮毂侧连接螺栓的仿真分析发现,预紧螺栓时螺栓内部轴向应力先逐渐增大,拧紧螺母期间保持不变,卸载拉伸器拉伸力时变小,发生回弹现象;并与实测结果对比,仿真分析方法计算的回弹系数为1.142,实测为1.128,相对误差仅为1.24%,验证了该仿真方法的准确性,从而量化了针对不同模型的螺栓预紧力下降的数值,进一步提高了液压拉伸器张拉螺栓的精度。另外,该仿真方法收敛性好,可以帮助行业摆脱繁重的测试标定工作,依靠简单的数值仿真分析制定一系列诸如螺栓回弹系数等数据库。The connecting bolts of key components of wind turbine are often pre-tightened by hydraulic tensioner in order to ensure the pretension precision of axial force of the bolts.However,owing to the change of structural stiffness of the key components before and after pretension,the axial force reduces.Therefore,the simulated analysis of the whole process of the bolt pre-tightened by hydraulic tensioner was established to simulate the process of stretching the bolt,tightening the nut and withdrawing the tensioner,and analyze the change of axial stress of the bolt in the process of stretching,pretension and reduction,taking into consideration of the influence of contact surface roughness on reduction of pretension force of the bolt.After the simulated analysis of connecting bolt at the hub side of variable pitch bearing of a certain model,it is found that the axial stress inside the bolt increases gradually during pre-tightening of the bolt,and remains unchanged during tightening of the nut,decreases during unloading of the tensioner,and the pretension force is reduced.The pretension reduction coefficient calculated in accordance with the simulated analysis method is 1.142 and the actual measurement is 1.128,which verifies the reliability of the simulation method,thus quantifies the decreasing value of pretension force for different models,and further improves the tensioning accuracy of the hydraulic tensioner for the bolt.In addition,the simulation method with good convergence can help this industry get rid of the burdensome testing and calibration works,and rely on simple numerical simulation analysis to develop a series of databases such as the pretension reduction coefficient of the bolt.

关 键 词：风力发电机组 液压拉伸器 螺栓轴力 回弹系数 仿真分析 

分 类 号：TM315[电气工程—电机]