缆索承重桥并列索尾流致气弹失稳研究  

Study on wake-induced aeroelastic instabilities of parallel cables in cable-supported bridges

作　　者：杜晓庆[1,2] 吴葛菲 林伟群 代钦[2,3] Du Xiaoqing;Wu Gefei;Lin Weiqun;Dai Qin(Department of Civil Engineering,Shanghai University,Shanghai 200444,China;Aerodynamic Flow Control Research Center,Shanghai University,Shanghai 200444,China;Shanghai Institute of Applied Mathematics and Mechanics,Shanghai University,Shanghai 200072,China)

机构地区：[1]上海大学土木工程系,上海200444 [2]上海大学风工程和气动控制研究中心,上海200444 [3]上海大学上海市应用数学和力学研究所,上海200072

出　　处：《土木工程学报》2020年第8期57-63,共7页China Civil Engineering Journal

基　　金：国家自然科学基金(51578330,51978392)。

摘　　要：为了研究表面粗糙度和雷诺数对并列索尾流致气弹失稳的影响规律,以圆心间距为4D(D为圆柱直径)的双圆柱为研究对象,通过风洞试验,在风向角α=0°~20°、雷诺数Re=18000~168800,研究下游圆柱发生尾流失稳的起振条件、振动幅度及运动轨迹等振动特性,分析增大阻尼比对尾流失稳的减振效果,探讨了圆柱表面粗糙度和雷诺数对尾流失稳的作用效应。研究表明,下游圆柱在不同的风向角及风速条件下会出现尾流驰振和尾流颤振2种气弹失稳形式;增大阻尼比对尾流驰振有明显的减振效果,但对尾流颤振的影响较小。尾流致气弹失稳有明显的雷诺数效应,随着雷诺数的增大,下游圆柱的振动形式会由尾流驰振转变为尾流颤振。增加上游圆柱表面粗糙度对下游圆柱气弹失稳的影响较小;而增大下游圆柱表面粗糙度,则会明显降低下游圆柱出现尾流失稳的可能性,并会使发散性振动转变为"限幅限速"振动。To investigate the effects of the surface roughness and the Reynolds number on the wake-induced aeroelastic instabilities of parallel cables,two staggered circular cylinders with a center-to-center distance of 4 were studied by wind tunnel tests.The incidence angleαvaried from 0°to 20°,and the Reynolds number Re ranged from 18000 to 168800.The vibration conditions,maximum amplitudes,and vibration trajectories of the downstream cylinder were discussed.The effects of surface roughness,Reynolds numbers,and damping ratios on wake-induced instabilities were analyzed.The results show that two types of aeroelastic instabilities,namely,the wake-induced galloping and the wake-induced flutter,can be found;an increased damping ratio has an obvious suppression effect on wake-induced galloping but has little effect on wake-induced flutter.The Reynolds number effects are observed,differently with the transition from the wake-induced galloping to wake-induced flutter at certain conditions.Besides,the larger surface roughness of the upstream cylinder has limited influence on the wake-induced aeroelastic instabilities.While for larger surface roughness of the downstream cylinder,the possibilities for the wake-induced aeroelastic instabilities decrease obviously;the phenomenon of divergent aeroelastic instability transforms into a"limited-amplitude and limited-velocity"vibration.

关 键 词：缆索承重桥 并列索 风洞试验 气弹失稳 粗糙圆柱 雷诺数效应 

分 类 号：U448.25[建筑科学—桥梁与隧道工程]