1000kV特高压钢管构架雷暴冲击风致振动响应研究

1000kV钢管构架属于风敏感结构,风与结构的相互作用十分复杂,风荷载常常是设计的主要控制荷载。本文以某一特高压钢管构架为工程背景,详细研究了冲击风风场的数值模拟方法,应用Wood竖直风剖面方程与Holmes经验模型模拟平均风场,以及使用稳态高斯随机过程模拟冲击风脉动风场,使得模拟的风场与实际的雷暴冲击风较为一致。利用精确的有限元模型,获得了结构的自振动力特性,在时域内得到了构架风致振动响应时程。研究了结构位移平均值、位移均方根值和加速度均方根值的分布特点,同时计算比较了不同风场时构架典型节点的风振系数。通过研究,揭示了1000kV钢管构架的风致振动特性,结果可作为构架结构抗风设计的参考。

Wind-induced dynamic response of large steel tube frame for l000kV UHV transmission lines to thunderstorm downbursts

With the complex interaction between wind and structure,1000kV steel tube frame belongs to wind-sensitive structures and the wind load becomes the main problem of the structure design.Based on the engineering background of a large steel tube frame for 1000kV UHV transmission lines with a 64m high,54m span.This paper presents a deterministic-stochastic hybrid model to simulate a downburst.Wood’s velocity profile for the vertical profile and Holmes’ empirical model are utilized to generate the mean wind.The fluctuation is generated by stationary Gaussian stochastic process.A precise finite element model was established and the vibration characteristics of structure have been obtained,then the wind-induced vibration responses of structure were obtained in the time domain.The characteristics of mean displacement,RMS displacement and RMS acceleration at different nodes of structure have been analyzed in detaile.Meanwhile,the wind-induced vibration coefficient at important nodes of frame for different wind environment were also studied and compared,respectively.Through the research,some characteristics of wind-induced dynamic responses of 1000kV steel tube frame were revealed,the procedure and the results presented in this paper can be applied for the design of large steel tube frame structures.