导线挡距对转角输电塔承载力性能影响研究

Investigation on Effects of the Cable Span on the Force-bearing Capacity of Transmission Angle-tower

研究了导线挡距对转角输电塔承载力性能的影响。建立了一塔两线的输电塔线体系分析模型,采用NewtonRapshon迭代法进行了塔线体系的几何非线性承载力分析。以某220kV大跨度转角输电塔为实际工程背景,研究了导线挡距变化下结构的非线性承载力性能。进一步进行了导线挡距效应的参数研究,考察了相邻挡距导线的挡距变化对塔身主要受力构件的轴应力的影响。研究表明转角输电塔主要受力杆件的轴向应力随着长导线挡距的变化而发生线性变化。即使对于同一输电塔而言,结构中主要受力杆件的承载力状况存在很大差别。在设计分析评估中有必要针对其具体受力特性进行详细的非线性有限元参数研究以确定各个杆件的不利荷载工况和优化的导线参数。

The effects of the cable span on the force-bearing capacity of a transmission angle-tower are actively investi- gated in this study. The analytical model of a truss tower and two lines are constructed and the Newton-Rapshon iteration approach is utilized to carry out the geometric nonlinear computation. A 220 kV large span transmission angle tower is taken as the example to investigate the nonlinear force-bearing capacity with different cable spans. Furthermore, the effects of cable spans are studied through parametric investigation to understand the axial stress variations of major mem- bers. The made observations indicate that the axial stresses of the major members vary linearly with the increasing cable span. As far as the same transmission tower is concerned, the force-hearing capacities of the major members are quite dif- ferent. It is essential to conduct the nonlinear finite element analysis to determine the disadvantage loading cases and opti- mal cable parameters in the structural design, analysis and evaluation.