Effect of cross beam in Vortex-Induced vibration and flutter analysis at large attack angle for the twin-deck bridges

Twin deck bridges are often required to construct, particularly for large spans and one-way movement of vehicles. The gap between the two decks is the most critical in the combined deck/bridge response. Nevertheless, this twin deck is vulnerable to vortex-induced vibration because the central slot modifies the flow profile surrounding a bridge girder. In addition, the large spans are also susceptible to the flutter effects of wind. Therefore, the study uses computational fluid dynamics to explore the impact of twin decks with cross beams on aerodynamic coefficients, flutter instability, and vortex-induced vibration. The features of vortex characteristics have been investigated and inferred in the current study for two structures: with and without cross beams at various effective angles. The research findings reveal that the vibrating frequency at the lock-in region is identical for installing cross beams. However, in the structure where the cross beam has not been used, the vibrating frequency exceeds the lock-in frequency at every effective angle. Still, the flow that passes through the cross beam extracts considerable energy from the flow field. The research findings revealed that the vibrating frequency at the lock-in region is identical for installing cross beams. This installation also beats the flutter instability by increasing critical flutter, which makes it a popular idea for mitigation purposes. Therefore, in these regards, the framework and solution are sustainable for bridge responses under vortex and flutter domains.