【摘要】 为研究风雨共同作用下拉索的气动力特性,以之江大桥为背景,通过对斜拉索的三维刚性节段模型做测力、测压风洞试验,得到4种表面形态下的拉索在不同风向角时的平均和脉动风压系数,结果表明:水线位置强烈影响拉索表面的风压系数分布,靠近水线附近气流的分离点会产生明显的改变,仅当上水线处于某些特定位置时,气动力系数变化明显,拉索才可能发生振动;用测压试验的风压系数积分得到的阻力系数要比测力试验的小10%左右,这是测压试验无法获得气动力中的摩擦分量所导致的。更多还原

【Abstract】 To study the aerodynamic characteristics of stray cable under wind and rain,with Zhijiang bridge as the background,force and pressure experiments on the three-dimensional model of stay cable in wind tunnel were conducted,and mean and fluctuating wind-pressure coefficients with 3 kinds of surface morphology under different wind direction angles were obtained.The results show that the rivulet position would influence the pressure coefficient distribution of cable surface strongly,and the separation point of flow nearby the rivulet will be changed obviously.When the rivulet is in some special positions,the aerodynamic coefficients will change obviously and the cable will vibrate;the drag coefficient obtained from integration of wind pressure coefficient by pressure experiment is 10% less than that from force experiment,as the friction number can’t be got from the pressure experiment.Necessary numerical reference and theory basis are provided to establish more precise theoretical model and study the efficiency of rain-wind-induced vibration damping measures.The results can provide guidance for the wind-resistant design and safe production of long-span cable-stayed bridges.更多还原