钢管塔杆件涡振对节点板疲劳寿命影响研究

煤炭开采对电力需求日益增大，电网工程不断扩大，钢管塔结构数量不断增多，结构疲劳失效会影响煤矿供电安全。针对钢管杆件涡振引起节点板疲劳开裂事件，进行了周边环境分析、涡振频率识别、涡激力计算、节点板实体模型应力分析以及最短开裂时间估算等工作。研究表明：当杆件弱轴涡振时，节点板中间位置加劲肋最外缘处有明显的应力集中，最大应力幅可达77.83MPa，经疲劳寿命计算，开裂节点板加劲肋附近区域理论上有可能在4～5个月的时间内发生疲劳开裂，这与断口电镜扫描提示的多源疲劳开裂相吻合。为避免此类事件的发生，应当从规范化涡振幅值控制指标、研发更为灵活的涡振特征监测手段着手开展后续工作。

Study on Fatigue Life of Joint Plate Induced by Vortex-induced Vibration of Steel Tube Member

In view of the fatigue cracking of joint plates caused by vortex-induced vibration of steel tubular members in UHV engineering, the surrounding environment analysis, Vortex frequency identification, vortex-induced force calculation, stress analysis of the solid model of the joint plate and the estimation of the minimum cracking time are carried out. The results show that there is obvious stress concentration at the outermost edge of the stiffening rib in the middle of the joint plate when the member occurring weak axis vibration. The maximum stress amplitude can reach 77.83 Mpa. In theory, the fatigue cracking near the stiffening rib of the cracked joint plate may occur within 4-5 months, which is consistent with the multi-source fatigue cracking indicated by SEM. In order to avoid the occurrence of such events, the following work should be carried out by standardizing the Vortex amplitude control index and developing more flexible vortex characteristic monitoring means.