针对高压输电塔的断线张力问题采用有限元方法(FEM)进行分析,建立输电塔、输电线以及地面的有限元模型.利用单元生死方法来模拟输电线的突然断裂,采用摩擦和接触来模拟跌落导线与地面的作用,获得输电塔线体系的断线响应和断线张力,并将断线张力结果与规范、文献中的方法进行比较.分析发现,当紧靠断线档的绝缘子摆幅达到最大时,输电线路的各种响应如绝缘子轴力、输电塔的顺线向剪力等几乎同时达到峰值.在只考虑静力作用的情况下,规范的断线张力数据大于有限元计算结果,基于曲线法的数据和计算结果非常接近;若考虑断线的动力冲击作用,则规范和曲线法的数据均比有限元结果小很多.
The finite element method (FEM) was employed to solve the broken wire problem of high voltage transmission tower. The finite element model including transmission tower, transmission line and the ground was conducted. The method using the death of cable element was used to simulate the sudden breaking of transmission line. The friction and contact were considered to simulate the interaction between the dropping wire and the ground. Then the responses of transmission tower-line system due to wire breakage were obtained and the broken wire loads were calculated. These broken wire loads were compared with the loads calculated from the codes and literatures. When the sway amplitude of insulator adjacent to the broken span reaches maximum, the responses of transmission line such as the axial force of insulator and along-line shear force of tower will reach their maximal values at the same time. If the static effect is considered, the broken wire loads obtained from codes are larger than the loads from FEM and the broken wire loads calculated based on the curve method and FEM are very close. If the dynamic impact effect is considered, the broken wire loads from codes and the curve method are much smaller than those from FEM.