输电塔线体系断线非线性动力分析

摘要

以某500 kV高压输电线路为研究对象,建立三塔四线输电塔-线体系精细化有限元模型,在考虑跌落导(地)线与地面碰撞接触基础上,对其进行了不同断线位置以及不同断线根数的隐式非线性动力分析.结果表明:断线点位置对断线瞬间的冲击作用影响较小;断线后断线一侧张力衰减系数随着导线挂点位置增高而单调递减;未断线一侧张力衰减系数随着挂点位置增高先减小后增大;耐张塔张拉作用系数远大于直线塔;耐张塔的断线动力放大系数在1.1～1.5.在断多根线的最不利工况下研究了耐张塔的扭转破坏和弯曲破坏两种失效模式.%Taking a 500 kV high-voltage transmission line as a study object,a fine finite element model of a transmission tower-line system was established.Considering collision and contact between a dropped wire and ground,nonlinear dynamic analyses of the system with different break points and different numbers of broken wires were performed.The results showed that the break point location has little effects on the impact action of broken wire;the tension decay coefficient of the broken wire decreases with increase in the height of the hanging point position,while that of the unbroken wire decreases first and then increases with increase in the height of the hanging point position;the tension coefficient of a strain tower is much larger than that of the tangent tower;the dynamic amplification coefficient of a strain tower is 1.1-1.5.Finally,the torsional failure mode and bending failure one of a strain tower were studied under the most unfavourable working conditions of multi-wire breakage.