大跨度桥梁主梁沿跨向涡激振动响应计算

Calculation of Spanwise Vortex-Induced Vibration Responses of Long-Span Bridge Girder

为向抑振提供准确的参考数据,基于单自由度涡激振动经验线性模型,结合主梁振型、阻尼和涡激力相关性,导出了主梁沿跨向竖向、扭转涡激振动响应,建立了大跨度桥梁主梁沿跨向涡激振动描述体系,并探讨了节段模型涡激振动识别气动参数的方法.以一大跨度斜拉桥为例,计算了主梁在不同风攻角下涡激力相关性及沿跨向竖向、扭转涡激振动响应.结果表明,受涡激力相关性作用,涡激振动振幅沿跨向衰减较快.

To provide accurate reference data to vibration restraint, based on the one-dimensional experienced linear VIV （vortex-induced vibration） model the vertical and torsional VIV spanwise responses of a bridge girder were deduced by synthetically considering factors such as mode shape, damping ratio and vortex-induced force correlation. A method was proposed to describe the VIV spanwise responses of a long-span bridge girder. A method to identify the aerodynamic parameters in the experienced linear VIV model through a section model test was discussed. By taking a long-span cable-stayed bridge as an example, the aerodynamic parameters were identified. In addition, the vortex-induced force correlation and the vertical and torsional VIV responses were calculated under different wind attack angles. The research result shows that the response amplitude of VIV influenced by the correlation decreases drastically with the increase of a spanwise distance.