基于可靠度的输电塔抗风优化研究

Study on the Reliability-based Wind Resistant Optimization of Transmission Line Towers

提出一种基于可靠度约束的输电塔实用抗风优化设计方法.首先,识别出体系的失效模式并找出关键杆件同时提取各失效模式对应的安全余量方程,计算各失效模式的可靠指标.然后,对可靠度不满足的失效模式通过加强关键杆件的方法进行优化.最后,对各失效模式进行综合求出体系可靠指标,若体系可靠度满足要求则优化结束,若体系可靠度不满足则通过优化最小可靠指标的失效模式来提高体系可靠度直到满足为止.编制程序对塔架进行了若干个风速的优化,分析结果表明:1)在完整失效路径上存在关键的破坏杆件,对关键杆件进行优化可以有效地提高体系可靠度;2)这是一种直接消除结构薄弱点的优化,优化效果好;3)随优化风速的增大,优化的效率将变低;4)方法计算简单,结果合理.

A practical design method was proposed for the reliability-based wind resistant optimization of transmission line towers. Firstly, the failure modes and their key elements were identified, and their safety margin equations were established. Second, the failure modes with a reliability index of less than the target reliability index were optimized by strengthening its key element. Lastly, the system reliability in- dex was calculated, and the failure mode with the least reliability index would be optimized if the system reliability index was less than the target reliability. An optimization example of a tower under several wind speeds was given and the results show. 1） there were key elements in the whole failure path, and the structure would be well strengthened if the key element was strengthened^2） it was a method in which the weak points were eliminated directly to strengthen the whole structure and it was very effective; 3） as the wind speed increased, it would be less effective; and 4 the method was simple and its results were reasonable.