Simulation of the additional damping characteristics of underwater heave plates for mitigating long-span bridges vibration

The underwater heave plates (UHPs), which are suspended beneath the bridge by flexible cables, can be temporarily utilized to mitigate bridge flutter. This study employs a simulation method to investigate the additional damping characteristics of the UHPs for controlling bridge vibration under various conditions. An analytical model including a rigid bridge deck, square heave plates, and suspension cables is developed. Detailed calculation steps for the system's response under impulsive conditions are provided. The accuracy of the developed simulation model and computational program is confirmed by the experiments for a simplified bridge deck. The control effects of the UHP's dimensions, mass, and cable stiffness on the deck's torsional vibration are analyzed under different torsional amplitudes and frequencies. Explicit formulas for determining the UHP mass, as well as the corresponding maximum cable force and damping ratio, are derived, and their accuracy are validated by comparing with the directly simulated results. The proposed simulation method simplifies the research process and improves overall efficiency. It facilitates the rapid optimization of the UHP's mass corresponding to the best control performance. This research provides valuable insights for designing, applying, and promoting UHPs in bridge flutters.