输电塔结构的动力稳定性研究

作为一种重要的生命线工程,输电线路的破坏会造成巨大的经济损失。统计显示,风荷载作用下输电塔结构的动态侧倾失稳是输电线路经常发生的破坏形式之一。因此,对风作用下输电塔结构的失稳破坏进行研究有着十分重要的意义。本文应用谐波叠加法模拟脉动风场,分别采用Budiansky-Roth准则和动态增量法(IDA)结合位移相等准则这两种方法,基于ANSYS的非线性屈曲分析和时程分析模块,对沈阳某输电塔的抗风动力稳定性进行了研究。结果表明,风的动力特性对结构稳定性影响较大,现行规范中按等效静力风荷载进行计算是偏于不安全的。

Study on Dynamic Instability of Transmission Tower

As one of important life line systems,the damage of transmission tower could cause great economic loss. According to the statistics,lost stability under dynamic wind load is one of the most usual destruct form in the construction of transmission tower. So,the research in this aspect is very meaningful. In this paper,we used the fluctuating wind field simulated by harmonic wave superimposing method,based on the nonlinear buckling analysis and the transient analysis package of the finite element program ANSYS,researched the dynamic stability of a transmission tower in Shenyang by two kinds of methods-Budiansky-Roth criteria and incremental dynamic analysis combining with displacement equivalency criteria. The results show that the dynamic characteristic of wind has a remarkable effect on the stability of the transmission tower,and the current criterion used in the design of transmission tower is unsafe.