Evolution laws of distributed vortex-induced pressures and energy of a flat-closed-box girder via numerical simulation

This article investigates the vertical vortex-induced vibration of a flat-closed-box girder using numerical simulation method. The accuracy of simulation results is verified at first by comparing the displacement responses and vortex-induced force of vertical vortex-induced vibration with those obtained in a previous wind tunnel test of large-scale sectional model. The precision of extracting the vortex-induced pressures from the surface pressures and decomposing the vortex-induced pressures via the mathematical model is validated later. Subsequently, the vortex-induced pressures and energy distribution, and the evolution laws of vortex-induced pressures and energy are discussed. The results show that the linear aerodynamic negative damping and nonlinear aerodynamic positive damping are key factors of the rapid development of vortex-induced vibration and the self-limiting phenomenon separately. The positive aerodynamic damping is mainly provided by the lower surface and the middle of the upper surface, and the negative aerodynamic damping is primarily provided by the middle and downstream of the upper surface.