摘要
螺栓松动是强风区和舞动区输电铁塔横担损坏的主要原因,通过开展三种型式输电铁塔双螺母螺栓的横向振动试验,获得了双螺母螺栓的预紧力时程曲线,分析了上、下螺母安装扭矩比例对螺栓预紧力衰减特性的影响规律。下螺母与上螺母安装扭矩之比为25%时,普通双螺母螺栓的防松性能最佳。完成了输电铁塔横担在舞动工况下的横向振动试验,确定了铁塔横担螺栓松动顺序和松动位置的分布规律。舞动荷载作用下横担下平面螺栓易发生松动,其中下平面主材与固定端连接螺栓、横担端部挂点处杆件连接螺栓的松脱现象最为严重,建议设计时进一步提高横担下平面主材及斜材连接螺栓的防松性能。
Loosing of bolted joints is the main reason for the cross arm damage of transmission towers in strong wind areas and conductor galloping areas. Transversal vibration tests on three types of double-nut bolted joints used in transmission towers were carried out. The effect of the ratio between the torques of top nut and bottom nut on the pretension reduction characteristic of double-nut bolts was analyzed. The time histories of the pretension of double-nut bolted joints were obtained. The optimal ratio of 25% between the torques of top nut and bottom nut in the bolted joint of transmission towers was proposed. Transversal vibration tests on the cross arm of the transmission tower in conductor galloping load case was completed. The loosing order and the location distribution of loosing bolts of the tested cross arm were determined. It is shown that the bolts in the bottom plane of the cross arm are easier to be loosen in galloping load case,especially for the connected bolts between the main member and the fixed points,as well as for the connected bolts between members at the suspension points at the end part of the tested cross arm. It was suggested that the anti-loosing capability should be further enhanced for the connected bolts of the main members and the diagonal members at the bottom plane.
作者
杨风利
李正
张大长
朱彬荣
王旭明
YANG Fengli;LI Zheng;ZHANG Dachang;ZHU Binrong;WANG Xuming(China Electric Power Research Institute,Beijing 100055,China;College of Civil engineering,Nanjing University of Technology,Nanjing 210009,China)
出处
《振动与冲击》
EI
CSCD
北大核心
2018年第10期164-171,共8页
Journal of Vibration and Shock
基金
国家自然科学基金(51408568)
国家电网公司科技项目(极端环境条件下强风区输电线路风荷载特性和铁塔结构研究)
关键词
输电铁塔
螺栓
横向振动
预紧力
安装扭矩
Transmission tower
bolt
transversal vibration
pretension
installation torque
