独塔斜拉桥钢拱塔竖转施工风致抖振响应分析

Analysis of the Wind-induced Buffeting Response of Steel Arch Pylon of Single Tower Cable-stayed Bridge During Vertical Rotation Construction

针对独塔斜拉桥钢拱塔竖转过程中由风荷载引起的振动问题,以武汉市高新二路独塔斜拉桥竖转施工为研究背景,利用有限元分析软件ANSYS对等待挂索的钢拱塔进行风致响应分析.首先运用ICEMCFD和FLUENT结合的方式模拟计算钢拱塔截面在多个风攻角下的静力三分力系数;接着选择线性滤波法进行脉动风模拟,通过MATLAB计算得到钢拱塔关键节点的脉动风速矩阵,并绘制风速时程曲线.根据脉动风速时程曲线计算抖振力的大小并进行时域化处理,在有限元模型上施加风荷载,用瞬态分析法对钢拱塔进行抖振时域分析,获得钢拱塔的振动响应.计算分析结果表明,在等待挂索的1个月时间内,钢拱塔在风荷载作用下的稳定性和安全性是可以得到保障的.

Taking the single tower cable-stayed bridge on Gaoxin 2nd Road in Wuhan as the research background,this paper studies the wind-induced vibration problem during the vertical rotation construction of steel arch pylon of single tower cable-stayed bridge and analyzes the wind-induced responses of steel arch pylon waiting for installation of cables using the finite element analysis software ANSYS.Firstly,the static force coefficients of the arch section for different wind attach angles are calculated by the combined use of ICEMCFD and FLUENT.By using MATLAB,linear filtering method is adopted to simulate the fluctuatng wind to calculate the fluctuating wind matrix of key nodes of the steel arch pylon and the time series of wind speed are graphed.The buffeting forces are computed based on the time series of wind speed and then transformed into the time domain.Finally,wind loads are applied to the FEM model in ANSYS and the wind-induced vibrations of the steel arch pylon are obtained by the time domain analysis of buffeting using the transient state analysis method.The results shows that the stability and security of steel arch pylon under wind load can be guaranteed for the one month wating period for the installation of cables.