Vortex-Induced Vibrations and Mechanism Analysis of Central-Slotted Box Girders with Different Aerodynamic Shapes

Central-slotted box girders have been widely applied in long-span bridges, such as the Çanakkale Bridge and the Xihoumen Bridge, due to their excellent flutter stability. However, their poor vortex-induced vibration (VIV) performance has attracted considerable attention from researchers. Considering that VIV is highly sensitive to the aerodynamic shape of the girder, this study conducted both wind tunnel experiments and numerical simulations on bare central-slotted box girders with various aerodynamic shapes. Different slot widths, inclined-web angles near the central slot, and wind fairing angles were considered. The VIV performance of these girders with different aerodynamic shapes was first investigated experimentally. Furthermore, using the CFD software ‘VXflow’, developed based on the Vortex Particle Method (VPM) by Guido Morgenthal, the mechanisms of VIV for the bare girders with different aerodynamic shapes were further studied. Overall, the analyses of the VIV responses and mechanisms of various aerodynamic shapes provide valuable references for the aerodynamic shape design of central-slotted box girders. Moreover, the FSI numerical simulation method based on VPM was validated, demonstrating significantly higher computational efficiency compared to conventional CFD approaches.