Numerical studies of the suppression of vortex-induced vibrations of twin box girders by central grids

作者：Li, Zhiguo; Zhou, Qiang^*; Liao, Haili; Ma, Cunming

来源：Wind and Structures, 2018, 26(5): 305-315.

DOI：10.12989/was.2018.26.5.305

• twin box girders
• vortex-induced vibrations
• central grids
• CFD simulation

A numerical study based on a delayed detached eddy simulation (DDES) is conducted to investigate the aerodynamic mechanism behind the suppression of vortex-induced vibrations (VIVs) of twin box girders by central grids, which have an inhibition effect on VIVs, as evidenced by the results of section model wind tunnel tests. The mean aerodynamic force coefficients with different attack angles are compared with experimental results to validate the numerical method. Next, the flow structures aroundY the deck and the aerodynamic forces on the deck are analyzed to enhance the understanding of the occurrence of VIVs and the suppression of VIVs by the application of central grids. The results show that shear layers are separated from the upper railings and lower overhaul track of the upstream girder and induce large-scale vortices in the gap that cause periodical lift forces of large amplitude acting on the downstream girder, resulting in VIVs of the bridge clerk. However, the VIVs are apparently suppressed by the central grids because the vortices in the central gap are reduced into smaller vortices and become weaker, causing slightly fluctuating lift forces on the clerk. In addition, the mean lift force on the clerk is mainly caused by the upstream girder, whereas the fluctuating lift force is mainly caused by the downstream girder.

• 出版日期2018-5
• 单位西南交通大学