斜拉索风雨振气动抑振措施的参数优化

通过风洞试验,研究了斜拉索空间位置、降雨量、风速等对斜拉索风雨振的影响,选定了振动最大时的参数,研究了作为气动抑振措施的螺旋线直径和缠绕间距两个参数对抑振效果的影响,并研究了附加不同参数螺旋线时斜拉索的气动阻力系数随雷诺数的变化规律,发现针对该研究选定的直径155 mm的斜拉索,斜拉索的水平角35°、竖向角25°、较小的降雨强度(10 mm/h)、特定的风速范围(无量纲风速60~100)下发生的振动最为激烈;在选定螺旋线间距的情况下,随着螺旋线直径的增大,其抑振效果趋于显著;在选定螺旋线直径的情况下,随着螺旋线间距的减小,其抑振效果趋于显著;附加螺旋线斜拉索的气动阻力系数随螺旋线直径的增大或螺旋线缠绕间距的减小而增大。在超临界雷诺数区域,附加螺旋线时的阻力系数均大于无螺旋线时的阻力系数。提出了优化的螺旋线设计原则。

Parameters optimization of aerodynamic countermeasure of rain-wind induced vibration of cables

By wind tunnel tests, cable altitude, rainfall intensity, wind velocity effects on rain-wind induced vibration of cables on cable-stayed bridge were studied. Set cable model when it got the largest vibration amplitude, the two parameters, helical line diameter and twine space, effects on rain-wind induced vibration of cables were studied, and aerodynamic drag force coefficients of cable with different helical line were measured in different Reynolds number range. Results show that for cable model with diameter of 155mm in this research, under the parameters composing of horizontal angle 35°, vertical angle 25°, small rainfall intensity (10mm/h) and certain wind velocity (non-dimensional wind velocity 60~100), cable vibration gets the largest amplitude. Fix the twine space of helical line, vibration control effect trends to evident when the diameter increases; and fix the diameter of helical line, when the twine space decrease the vibration control effect trends to evident. The aerodynamic drag force coefficient of cable with helical line increases, when helical line diameter increases or the twine space decreases. The optimization design rule of helical line was pointed out.