摘要 柔性大跨主梁在低速横风作用下易发生涡激振动,尽管不会导致毁灭性的破坏,但会引起结构疲劳或影响正常使用。基于Scanlan非线性涡振模型,引入Wilkinson涡激力相关性函数,推导大跨主梁沿跨向锁定状态竖向、扭转涡振一次理论近似解,分析相应气动参数识别方法。以一大跨斜拉桥为例,根据主梁节段模型涡振试验识别气动参数,计算沿主梁跨向竖向涡振响应。
Abstract The flexible long-span bridge girder is easy to occur Vortex-Induced Vibration(VIV), which is influenced by cross-wind at relative low speed. Although VIV may not be catastrophic, it may be fatiguing to structure and disconcerting to users. The first-order approximate theoretic solution on lock in is deduced by using Scanlan’s nonlinear VIV model and Wilkinson’s correlation function of vortex shedding force to describe vertical and torsional vibration of girder. Moreover, the method is discussed to identify aerodynamic parameters from section model test. Lastly, the spanwise vertical and torsional VIV response of a long-span cable stayed bridge girder are calculated from girder’s section mode VIV test.