新型斜拉桥和摩天轮组合结构动力性能分析

Analysis on Dynamic Features of Composite Structure of New Cable-stayed Bridge with Giant Wheel

慈海桥是由新型斜拉桥和摩天轮组合而成的结构体系,文中介绍了慈海桥的工程概况,分析了斜拉桥存在的三种几何非线性因素:拉索垂度效应、大位移效应和梁柱效应,建立了新型斜拉桥和摩天轮组合结构的三维有限元模型,提出了每种几何非线性因素的处理办法,分别对摩天轮、新型斜拉桥和整体组合结构进行了模态分析,求得了各自和整体的自振频率,分析了单个结构和整体结构的自振特点,指出组合结构具有分段密集的频谱,振型复杂,在低阶频率中,摩天轮振型所占比例较多,斜拉桥所占比例较小,且多数与摩天轮的振动耦合在一起。

Cihai Bridge is a new structural system consisted of cable-stayed bridge and giant wheel. The general situation of Cihai Bridge is introduced. Three kinds of geometric nonlinearity lied in cable-stayed bridge are analyzed, which included the sag of cable, large displacement and the effect of beam-column. A FEM model of the composite structure is built and methods dealing with each nonlinearity factor are put forward. Model analysis of giant wheel, new cable-stayed bridge, the whole structure are carriedout individually. The mode shape and selffrequency are attained. The analysis is done on the feature of the dynamic performance. It is pointed out that the whole structure has a stepped condense spectrum and complex mode. In low-order frequency, the vibration of giant wheel covers a large part, while that of the cable-stayed bridges covers a small part and most of its vibration are coupled with that of the wheel.