To study the sensitivity of the vortex‐induced vibration (VIV) performance of the steel box girder to the Reynolds numbers ,a steel box girder cable‐stayed bridge was cited as an ex‐ample and the sectional models of the tw o different scales of 1∶50 and 1∶20 for the main girder of the bridge were established .The differences of the VIV performance of the main girder at the high and low Reynolds numbers were compared and analyzed through the wind tunnel tests and the in‐fluences of the damping ratios on the VIV performance were investigated .The mechanism of the differences of the VIV performance was studied ,using the numerical simulation techniques and the VIV performance was evaluated .The results reveal that when the damping ratios are little ,two vertical VIV zones appear in the tests at both the high and low Reynolds number and the amplitude of the VIV gradually decreases with the increase of the damping ratios .When the damping ratios reach the certain values ,the VIV disappears .When the damping ratios are about equivalent ,the locked wind speed and the starting and stopping wind speeds of the VIV corresponding to the max‐imum vibration amplitude of the high Reynolds number model are higher than the corresponding values of the low Reynolds number model .The vortex energy around the section of the model at the low Reynolds number is greater than that of the model at the high Reynolds number ,the vor‐texes around the models are many and the intensity of the vortexes is great .When the damping ra‐tios increase to 1 .16% ,the amplitude of the VIV can satisfy the wind design requirements .%为研究钢箱梁涡振性能对雷诺数的敏感性，以某钢箱梁斜拉桥为背景，建立2种尺度（1∶50和1∶20）主梁节段模型，通过风洞试验对比分析高、低雷诺数下主梁涡振性能的差异，研究阻尼比对涡振性能的影响，采用数值模拟技术对差异性进行机理研究，并评价其涡振性能。结果表明：阻尼比较小时，高低雷诺数试验均出现2个竖向涡振区；涡振振幅随着阻尼比的增加逐渐减小，当阻尼比达到某一值时，涡振消失；阻尼比大致相当时，高雷诺数模型的最大振幅对应锁定风速、涡振起振风速和止振风速均要高于低雷诺数的相应值；低雷诺数下断面周围旋涡能量较高雷诺数的大，模型周围旋涡多，强度大；阻尼比增至1．16％时，涡振振幅可满足抗风设计要求。
展开▼
