桁式加劲梁悬索桥抗风动力特性分析

大跨悬索桥的抗风性能在大跨悬索桥梁设计中具有非常重要的地位,而桁式加劲梁由于其优良的空气动力稳定性在大跨悬索桥中经常被采用。本文以湘西矮寨特大桥实际工程为背景,通过舍弃目前常用的单主梁、双主梁或三主梁模式而采用按实际桁架的构成建立仿真三维梁单元模型的方法建立了整体结构的三维分析模型,利用ANSYS有限元软件对该结构体系进行动力特性的分析计算,得到了该桥型的横向、竖向、主缆、扭转以及耦合振动的频率和振型。分析结果表明,由于桁架结构和索、杆的共同工作效应,使得这种体系的整体刚度好,特别是主缆抵抗变形能力强,动力性能优越,具有很好的抗风性能,分析结果将会为该桥梁进一步的抗风、抗震等设计提供有益的参考。

Analysis on Resisting Wind Dynamic Characteristics on Suspension Bridge with Truss Beam

The ability of resisting wind is very important in the design of Suspension Bridge,Because the truss beam has very good aerodynamic characteristics,it is often used in Suspension Bridge.This paper is based on the actual project-AiZHai Suspension Bridge,by using the commercial software ANSYS to analysis its dynamic characteristics.The natural frequency and modes are acquired.Because of the cable,the pole and truss structure work together harmonic,this type of structure have good characteristics,such as rigid of the whole structure,ability of resisting deformation of cable,dynamic performance of cable etc.The conclusions show that application of space truss structure into suspension bridge has good performance in resisting wind.The result of analysis will give some useful reference for resisting wind and seismic study.