脉动风作用下塔线体系的风致响应特性分析

Wind-induced response analysis of tower line system under fluctuating wind

塔线体系是输电系统的基础,风载荷作为塔线体系所受的主要载荷,在风载荷下塔线体系的结构安全分析十分重要。考虑脉动风载荷的影响,采用Kaimal风谱与谐波叠加法,拟合确定了脉动风速,并考虑了风速沿高度的变化情况。基于ABAQUS有限元软件,建立“四塔五线”的典型耐张段模型,分析不同风速、风向角对于塔线体系结构动力响应的影响机制。通过对杆塔塔头位移、杆塔底座支反力以及塔线体系的应力集中部位的分析得出:随着风速的增大,重力塔与张力塔在两个方向的塔头位移幅值增大;随着风向角的增大,张力塔在两个方向的塔头位移幅值增大;重力塔在垂直于塔线体系方向的位移幅值增大,沿塔线体系方向的位移幅值先增大后减小,在45°时达到最大幅值。杆塔的应力集中点基本位于杆塔的钢材集中处。

Wind load is the main load of the tower line system which is the foundation of the transmission system.The structural safety analysis of the tower line system under wind load is very important.In this article,Kaimal wind spectrum and harmonic superposition method are used to fit the fluctuating wind speed,and the variation of wind speed along the height is considered.Based on ABAQUS finite element software,a typical tensive-segment model of“four towers and five lines”was established to analyze the influence mechanism of different wind speeds and wind direction angles on the dynamic response of tower line system.The tower head displacement,base support reaction and stress concentration of tower line system were analyzed respectively.The results show that the displacement amplitudes of gravity tower and tension tower in two directions increase with the increase of wind speed.With the increase of wind direction angle,the amplitude of tower head displacement increases in two directions.The amplitude of gravity tower displacement increases in the direction perpendicular to the tower line system,whereas it increases first and then decreases along the tower line system,reaching the maximum value at 45°.The stress concentration point of the tower is basically located at the steel concentration point of the tower.