导线断线对跨越架冲击系数的试验研究

Experimental study on the impact coefficient of wire impact on crossing frame

目前跨越架的设计方法多采用安全系数法,安全系数的实际取值与导线跌落冲击跨越架的冲击系数有关,现行标准中冲击系数的取值单一,没有考虑导线跌落高度的影响。针对上述问题,文中设计了格构式跨越架等效模型,在不同落线高度下,开展了导线冲击跨越架等效模型的冲击试验,研究跌落导线对跨越架的冲击系数的变化规律。试验结果表明,冲击过程具有瞬时性效应,冲击开始至峰值约0.02 s,冲击过程约持续0.3 s;导线冲击封网杆存在载荷不平衡现象;随着导线跌落高度的增加,封网杆跨中位置的峰值应变逐渐增大,但呈非线性变化,实际导线断线对跨越架的冲击系数随导线跌落高度变化而波动较大。

At present, the safety factor method is mostly used in the design method of the crossing frame,the actual value of the safety factor is related to the impact coefficient of wire impact on the crossing frame. The value of the impact coefficient is single in the current standard, and the effect of the drop height of the wire is not considered. In view of the above problems, the equivalent model of the lattice crossing frame is designed in this paper. The impact experiment of the equivalent model on the wire impact crossing frame was carried out at different height of the falling wire. The change rule on the impact coefficient of the falling wire impact on the crossing frame is studied. The test results show that the impact process has instantaneous effect, the time of impact beginning to a peak value is about 0.02 s, and the impact process is about 0.3 s.The process of wire impacting protective rod exist load imbalance phenomenon. With the dropping height of wire increases, the peak strain in the position of the protective rod gradually increases, but the change is nonlinear. With the dropping height of wire impact crossing frame increasing, there is a large range of change about impact coefficient.