带防撞栏杆扁平箱梁高阶模态涡激振动的CFD研究  

Investigation on vortex-induced high-mode vibrations of flat box girders with crash barriers based on CFD

作　　者：祝志文 石亚光 颜爽[1] ZHU Zhiwen;SHI Yaguang;YAN Shuang(Department of Civil and Environmental Engineering,Shantou University,Shantou 515063,China;WISDRI Engineering&Research Incorporation Limited,Wuhan 430000,China)

机构地区：[1]汕头大学土木与环境工程系,广东汕头515063 [2]中冶南方工程技术有限公司,武汉430000

出　　处：《振动与冲击》2021年第10期228-234,277,共8页Journal of Vibration and Shock

基　　金：国家自然科学基金(51278191);国家重点基础研究发展计划(2015CB057701)。

摘　　要：为研究大跨度桥梁常用扁平箱梁带防撞栏杆时的高阶模态涡激振动(VIV)特性,基于雷诺时均Navier-Stokes(RANS)方程、SST k-ω湍流模型和动网格技术求解扁平箱梁的绕流场并获得气动力,将Newmark-β算法代码嵌入到用户自定义函数(UDF)求解该气动力作用下的桥梁动力响应,开展了大带东桥主桥加劲梁断面高阶模态涡激振动响应的预测,模拟雷诺数为3.18×10^(4)~6.10×10^(4)。获得了扁平箱梁断面随折减风速变化的高阶涡振响应振幅根方差(RMS)曲线和加速度时程,预测了与文献较一致的高阶模态涡激振动锁定区间。研究了阻尼比和来流风攻角对扁平箱梁高阶模态涡振响应幅值和加速度的影响,表明随着阻尼比的增大高阶模态涡激振动响应逐渐变小甚至消失,而来流风攻角只有大于2°时才会发生显著的高阶模态涡激振动。In order to investigate the characteristics of the vortex-induced high-mode vibration(VIV)of a flat box girder,the flow field around the flat box girder was solved based on the Reynolds averaged Navier-Stokes(RANS)equation and the SST k-ωturbulence model in combination of the dynamic mesh technology.The dynamic response of the structure was solved by the Newmark-βintegration method which was embedded in Fluent user defined functions(UDFs).The estimation of high-mode VIV responses of the stiffened girder of the Great Belt East Bridge main crossing was carried out under the Reynolds number from 3.18×10^(4) to 6.10×10^(4).The study presents the time histories of acceleration responses and the RMS value of vibration amplitudes at various reduced wind speeds,and the lock-in region of VIV agrees well with that in literatures.Also,the effects of damping ratio and wind angle of attack on the displacement and acceleration responses of the stiffened girder were studied.The results show that as the damping ratio increases,the response of VIV becomes smaller and even finally disappears,while remarkable VIV can be recognized only when the wind angle of attack is larger than 2°.

关 键 词：大跨度桥梁 涡激振动(VIV) 计算流体动力学(CFD) 扁平箱梁 高阶模态 流固耦合 

分 类 号：U443.35[建筑科学—桥梁与隧道工程]