抑制斜拉桥拉索风雨激振的气动措施研究

在驰振理论的基础上,运用带有运动水线的二维拉索模型对风雨激振进行理论分析,得到了拉索发生风雨激振的充分条件、必要条件及临界发散风速。并将此分析方法运用到设有气动措施的拉索上,引入等效阻尼比指标对气动措施减振效果进行定量分析。结合静气动三分力试验和分析计算,对螺旋线、纵向肋条和椭圆环三种气动措施的减振效果进行评价分析,螺旋线、纵向肋条的减振效果好于椭圆环。通过人工降雨试验,对气动措施减振效果的分析方法进行检验。

A STUDY ON AERODYNAMIC CONTROL COUNTERMEASURES TO RAIN-WIND INDUCED VIBRATION OF CABLES IN CABLE-STAYED BRIDGE

Based on galloping theory,a theoretical analysis of rain-wind induced vibration is carried out by using a two-dimension mechanical model with movable rivulet,to obtain the sufficient condition, the necessar y condition and the critical wind speed of rain-wind induced vibration.With the same method,equivalent damping ratio is introdu ced to quantitantirely evaluate the effect of aerodynamic countermeasures to mitigate rain-wind induced vibration, and the eq uivalent damping ratios of helical wire cable, axially protuberated cable, elliptical discrete thick plates cable are calc ulated.Finally, the rain-wind induced vibration wind tunnel tests are conducted to verify the method.