山区覆冰输电塔线体系风致不平衡张力的研究

针对5B-ZBC1输电塔,采用数值试验的方法研究了风速、初始风攻角、输电塔高差和导线覆冰厚度对输电塔纵向不平衡张力的影响.作用在输电塔线上的脉动风时程是利用谐波合成法生成,通过改变高差、覆冰厚度,获得了输电塔上纵向不平衡张力的变化规律.该规律表明,在一些情况下现行规范规定所计算的输电塔不平衡张力偏小.在此基础上提出了山区这类塔型在雪荷载和风荷载共同作用下的纵向不平衡张力的理论公式.该公式的结果与数值试验结果相比误差在±6%以内,具有较好的精度.

Analysis of the Wind-induced Unbalance Tension of Iced TransmissionTower-line System in Mountainous Areas

A numerical experiment was adopted to analyze the effects of wind speed, initial wind angle, elevation difference and ice thickness on the longitudinal unbalance tension of transmission tower. Harmony-superposition method was used to simulate the fluctuating wind speed time series acting on the transmission tower line, and the law of unbalance tension was derived by changing elevation difference and ice thickness.The results have shown that, in some cases, the value of the longitudinal unbalance tension of the tower in existing electricity industry standard is smaller. Based on computational analysis, the theoretical formula of the longitudinal unbalance tension of towers subjected to wind and snow simultaneously was proposed. The errors of the formula are within ± 6% compared with numerical simulation. It has preferable accuracy.