雷暴冲击风作用下输电高塔风致振动特性研究

STUDY ON WIND-INDUCED DYNAMIC RESPONSE OF LONG-SPAN TRANSMISSION TOWER UNDER THUNDERSTORM DOWNBURSTS

输电高塔是风荷载较为敏感的结构,风荷载的合理选取往往成为设计的关键一环。文中以某一500kV大跨越塔为研究对象,利用混合随机模型,模拟了雷暴冲击风的三维矢量风场。建立了结构的有限元模型,得到了结构的自振频率和模态特性,并利用动力时程分析法在时域内研究了结构风致振动特性,获得结构位移和加速度的分布规律,分析了结构各高度的风振系数和建议风振系数取值。结构冲击风致振动特性可作为大跨越塔抗风设计的一种参考。

The transmission tower is a structure with relatively sensitive wind loads,and the reasonable selection of wind loads often becomes a key part of the design.Based on the research object of a 500kV long-span tower,the three-dimensional vector wind field is simulated by using the mixed stochastic model.The finite element model of the structure is established,the structural self-vibration frequencies and modal characteristics is obtained,and the dynamic wind-induced vibration characteristics are studied by dynamic time history analysis method.The characteristics of displacement and acceleration at different nodes of structure have been analyzed in detail.Meanwhile,the wind vibration coefficient at different height of transmission tower were also studied and compared,respectively.The impact of the wind-induced vibration characteristics of the structure can be used as a reference for wind resistant design of long-span crossing tower.