大跨斜拉结构拉索参数振动有限元仿真分析

Finite element simulation of parametric vibration of cables in long span cable-stayed spatial grid structures

斜拉索作为大跨斜拉结构的重要组成构件,其复杂振动特性会影响整体结构的受力性能.斜拉结构中拉索会发生参数振动现象在诸多文献中得到理论与试验研究证实.本文通过工程设计常用的有限元仿真,对一斜拉网壳结构建立有限元模型,分析该结构中拉索发生参数振动的可能性及其影响因素,并对拉索参数振动的两个特性进行理论分析:响应的"拍"现象、系统频率比在2的区间范围内均可发生参数振动.研究结果不仅可以指导大跨斜拉结构的设计施工,还能为拉索参数振动的抑制和控制提供参考意见.

Inclined cables are important components in the design of long span cable-stayed structures, and the vibration behavior of inclined cables affects the mechanical characteristics of the entire structure. The phenomena of parametric vibration of inclined cables in cable-stayed structures have been studied by many researchers with kinds of theoretical and experimental methods. In this paper, the finite element model of a cable-stayed latticed shell structure is established to investigate the behaviors of the parametric vibration. It focuses on the influence factor and its effects on the parametric vibration. This paper illustrates the mechanism of the beat phenomenon of the displacement of the cable and the reason for parametric vibration happens not only when the frequency ratio is equivalent to 2, but also in a certain range around it. The correlative results can provide basic guidelines for the design of cable-stayed structures and beneficial suggestions to control the occurrence of the parametric vibration.