风速水平空间相关性对长横担输电塔风效应的影响

摘要

以沿海某220 kV长横担角钢输电塔为原型，考虑沿横担向的脉动风速非完全相关性，采用谐波叠加法模拟该输电塔的风速时程，并基于准定常假定进行输电塔风振时域分析，得到了结构的风振响应和杆件内力。研究表明：考虑脉动风速水平向空间相关性后，横担产生显著的转角，塔头具有明显的扭转振动，并导致塔头的斜材内力增幅明显；然而，由于风速空间相关性的引入，顺风向整体脉动风载有所减小，使得全塔的风振系数减小，尤其是塔身的风振系数减幅明显。因此，长横担输电塔设计中应考虑风速水平向空间相关性对风效应的影响。%Taking a 220 kV long cantilever transmission tower as the research object,the dynamic wind velocity was simulated by using WAWS considering the effects of turbulent transverse space correlation (TTSC ).Based on the quasi-steady assumption,a numerical analysis in time domain was performed to obtain the time history of wind-induced responses of the structure and elemental stress responses of the tower.The results show that the existence of TTSC induces significant torsional angle,and arouses obvious torsional vibration of the tower.The stresses in diagonal members on the top of the tower also increase significantly due to TTSC.However,as along-wind fluctuating wind load reduces because of TTSC,the dynamic response factor of the whole tower,especially the tower body,decreases dramatically.Therefore,the influence of TTSC on wind-induced responses should be taken into consideration in the design of transmission tower.