盘形悬式绝缘子钢脚球头断裂及其尺寸优化的有限元分析

Finite Element Analysis of Fracture and Size Optimization of Steel Pin Ball of Cap and Pin Type Suspension Insulator

在雨雪大风等恶劣天气下,输电线路盘形悬式绝缘子掉串事故时有发生,钢脚球头部位的疲劳断裂是造成掉串事故的主要原因之一。对额定破坏载荷为160 kN的盘形悬式绝缘子钢脚(球头颈部过渡圆角半径为3.5 mm)通过UG建模,导入ANSYS Workbench中进行静力学分析。发现在钢脚球头颈部存在明显的应力集中,这是造成钢脚球头部位疲劳断裂的主要原因。通过对球头颈部过渡圆角半径进行优化,可以有效减小该部位的应力集中。当过渡圆角半径为7.1 mm时,钢脚球头颈部的最大应力下降22.4%,显著提高输电线路盘形悬式绝缘子串运行可靠性。

Under the severe weather conditions, such as rain, snow, wind and so on, string drop accidents of the cap and pin type suspension insulators in the transmission lines occur occasionally. Fatigue fracture of the steel pin ball is the main reason to cause the accidents above. The steel pins of cap and pin type suspension insulators with a rated failure load of 160 kN(ball transition circle radius is 3.5 mm) were modeled through the UG software and then imported into the ANSYS Workbench software for the static analyses. It was found that the stress concentration existed at neck of the steel pins ball, which was the main reason of fatigue fracture of the steel pins. By optimizing the transition ball radius, the stress concentration could be reduced apparently. As the optimal size of the transition fillet radius was set 7.1 mm, the maximum stress at neck of the steel pin ball was decreased by 22.4%, which should greatly improve the operation reliability of the cap and pin type suspension insulator strings in the transmission line.