螺旋线对斜拉桥斜拉索高雷诺数风致振动影响的试验研究

Experiments on the effect of helical line on the stay-cable vibration at high Reynolds number

斜拉索是斜拉桥的基本受力构件之一,其承受的风荷载占桥梁总体风荷载的比例很大,因此其风振问题是设计研究的重点。以风洞试验为研究手段,通过自行设计的斜拉索测振试验系统,对直径为120 mm的斜拉索模型和25种螺旋线拉索模型进行了刚性模型测振试验,得到了不同斜拉索模型振幅随雷诺数的变化规律。结果表明:斜拉索上缠绕螺旋线能减弱雷诺数效应;当螺旋线缠绕间距一定,随着螺旋线直径的增加,斜拉索振幅变化呈不完全单调的减小趋势;当螺旋线直径一定,随螺旋线间距减小,斜拉索振幅变化整体呈单调减小的趋势;随着螺旋线直径的增加和间距的减小,振动稳定性有所提高。

Cable is one of the basic construction members of a cable-stayed bridge. The wind loads on cables constitute a high proportion of total wind loads on the bridge,and the wind-induced vibration is an important problem of great concern in bridge design. Through a self-designed vibration test system for stay-cables,the vibration model tests for a rigid stay-cables model with diameter of 120 mm as well as for 25 kinds models of stay-cables wound with helical lines were conducted in a wind tunnel. The changing rule of the vibration amplitude along with the Reynolds number was analyzed. The results show that winding a helical line on the cable can reduce the Reynolds number effects on it. When the helical line winding spacing is constant,the amplitude trends to decrease along with the increase of helical line diameter. When the helical line diameter is constant,the amplitude trends to decrease along with the decrease of helical line winding spacing. The vibration stability is improved with the increase of helical line diameter and the decrease of helical line winding spacing.