悬索桥施工猫道非线性静风响应

Nonlinear Aerostatic Response of Catwalk of Suspension Bridge

为了使悬索桥施工猫道静风响应的研究更加接近真实,利用大型有限元软件ANSYS,建立了澧水河特大悬索桥施工猫道的有限元计算分析模型,对猫道进行了非线性静风响应研究。在猫道节段模型的静力三分力试验的基础上,考虑猫道结构的几何非线性和静风荷载的非线性,采用增量与内外两重迭代相结合的方法,编制了精确求解施工猫道静风失稳的计算程序,进而对澧水河特大悬索桥施工猫道进行了三维非线性静风失稳分析。研究结果表明:向上的升力作用可使猫道承重绳的张力逐渐开始松弛,导致小跨猫道扭转刚度减小;猫道发生静力扭转失稳的原因为减小的扭转刚度不足以抵抗空气力矩作用。

In order to make the study on aerostatic response of suspension bridge catwalk more realistic, based on the FEA software ANSYS, the FEA model of the catwalk of Lishuihe grand suspension bridge was established. Based on section model wind tunnel test for aerostatic tri-component force of catwalk, considered the geometric nonlinearity and aerostatic nonlinearity of catwalk of the bridge, the calculation program which can accurately calculate the aerostatic instability of catwalk of suspension bridge was established by the method of combining the incremental and internal and external iteration. And then the 3 D nonlinear static wind instability analysis for the catwalk of the bridge was performed. The research result indicates that （ 1 ） the lift force can make tension of load-bearing rope in catwalk gradually relaxes and the torsional stiffness of small span catwalk decreases ; （2） the reason of aerostatic torsional instability is that the decreased torsional stiffness is not sufficient to resist the aerial torque effect.