摘要
利用宏观检验、化学成分分析、显微组织检验、SEM形貌分析及有限元分析等试验方法对某220 kV输电铁塔横担绝缘子球头挂环断裂原因进行了试验分析。结果表明,基建安装时U形挂板与球头挂环连接螺栓预紧力过高,造成球头挂环无法绕U形挂板下端螺栓孔自由摆动;另一方面,球头挂环在加工过程中参数控制不当,组织中形成网状铁素体组织,使得材料脆性增大,抗疲劳性能下降。遇到导线风偏摆动时,在应力集中效应明显的球头挂环与杆部结合处优先开裂,并以疲劳的方式不断扩展,直至完全断裂。
The fractured ball head hanging ring used for cross arm insulator of 220 kV transmission tower is investigated by means of macrographic inspection, chemical composition analysis, microstructure analysis, SEM morphology analysis and finite element analysis. The result shows that the pre-tightening force of the connecting bolt between U-shaped hanging plate and ball head hanging ring is too high during infrastructure installation, which causes the ball head hanging ring unable to swing freely around the bolt hole of the lower end of the U-shaped hanging plate. Moreover, due to the improper control of the parameters of the ball head hanging ring during the manufacture process, the reticulated ferrite is formed in ball head hanging ring, which increases the brittleness of the material and reduces the fatigue resistance. In this way, when the wind deflection of the conductor is encountered, the joint between the ball head hanging ring and the rod with obvious stress concentration will preferentially crack, and the crack will expand in the form of fatigue growth until the ball head hanging ring is completely broken.
作者
安东
陈浩
张涛
谭晓蒙
谢利明
AN Dong;CHEN Hao;ZHANG Tao;TAN Xiaomeng;XIE Liming(Inner Mongolia Power(Group)Co.,Ltd.,Inner Mongolia Power Research Institute Branch,Hohhot 010020,China;Inner Mongolia Enterprise Key Laboratory of High Voltage and Insulation Technology,Hohhot 010020,China)
出处
《内蒙古电力技术》
2023年第1期66-70,共5页
Inner Mongolia Electric Power
基金
内蒙古电力(集团)有限责任公司科技项目“输电铁塔球头连接金具断裂机理及疲劳寿命提升关键技术研究”(2022-08)。
关键词
输电铁塔
球头挂环
预紧力
疲劳断裂
网状铁素体
transmission tower
ball head hanging ring
preload
fatigue fracture
network ferrite
