架空裸导线截面应力分析

Section Stress Analysis of Overhead Conducting Wires

为研究运行中钢芯铝绞线(ACSR)截面应力真实分布规律,利用有限元法对导线截面的应力分布情况进行分析。以九江叶家山-柘林水电站Ⅱ回220KV工程线路所使用的LGJ-240/40钢芯铝绞线为实际对象,建立三维实体模型和有限元模型。模型一端面限制x、y、z轴自由度,另一端面分别施加15%、20%、25%计算拉断力,同时分两种情况进行受力分析:钢芯铝绞线内各丝间无相对滑移及摩擦;钢芯铝绞线内各丝间存在相对滑移及摩擦。分析得到了钢芯铝绞线在两种情况下的截面等效应力分布情况。结果表明,当不考虑线内相对滑移及摩擦时,钢芯与铝股应力比约为3:1,截面等效应力呈圆环状由中心向外逐渐减小。当考虑线内相对滑移和摩擦时,钢芯与铝股应力比值约为5:1,截面等效应力呈中心对称分布。将分析结果与已有文献的理论和实验结果进行对比,验证了分析结果的有效性。

In order to study the true distribution law of the ACSR cross-section stress during operation,the finite element method was used to analyze the stress distribution of the conductor cross-section.Taking the LGJ-240/40 ACSR used in the II 220KV project of Yejiashan-Yanglin Hydropower Station in JiuJiang as the actual object,a three-dimensional solid model and a finite element model were established.One end of the model limits the degrees of freedom of the x,y,and z axes,and the other end exerts 15%,20%,and 25%to calculate the breaking force.At the same time,the force analysis is performed in two cases:each wire in the ACSR.There is no relative slip and friction;there is relative slip and friction between the wires in the ACSR.The distribution of the equivalent stress distribution of ACSR in two cases was analyzed.The results show that when the relative slip and friction in the wire are not considered,the stress ratio of the steel core to the aluminum strand is about 3:1.The equivalent stress in the cross section gradually decreases from the center to the outside.When considering the relative slip and friction in the wire,the stress ratio of the steel core to the aluminum strand is about 5:1,and the equivalent stress in the cross section is symmetrically distributed in the center.Comparing the analysis results with the theoretical and experimental results of the existing literature,the validity of the analysis results was verified.