基于涡激力偏相关的大跨度桥梁涡激振动线性分析方法

摘要

周期性旋涡脱落会使大跨度桥梁产生涡激振动,与旋涡脱落密切相关的涡激力沿跨向并不完全相关.基于Scanlan涡激力经验线性模型,研究了涡激力沿跨向的相关性.通过Fourier变换得到二维力谱到三维广义力谱的转换关系,定义了二维与原型桥梁涡振响应之间的折减系数,给出了将节段模型涡振试验结果应用到原型桥梁的具体理论方法.最后,通过不同缩尺比的节段模型风洞试验及全桥气弹模型风洞试验验证了本文理论的有效性.%Periodical wake vortices may cause vortex induced vibration of a long span bridge, the vortex-induced aerodynamic force produced by vortices is partial correlation along the span. Based on Scanlan's semi-empirical linear model, the correlation of vortex-induced aerodynamic force along span is studied. The inner-relation of force spectrum from 2D to 3D is found by Fourier transform, and reduced factor of vortex induced response between 2D to 3D is defined, and the methodology for applying modeling test results into prototype is discussed. Validity of proposed theory is proved by different scale sectional models and full aeroelastic model wind tunnel tests.