Multiple Controllers of Wind-Induced Oscillations of a Long Span Bridge

This paper discusses a new system of multiple synchronized dynamic attenuators (MSDA) that has been installed in the Rio- Niteroi bridge to prevent cross-winds of relatively low velocities set into vortex-induced oscillations on the lightly damped and long three continuous spans of the world's largest steel twin-box-girder bridge. The conceptual design of this passive control system along with its main geometric and physical characteristics is briefly described in the paper. The paper gives a short account on how an experimentally calibrated mathematical-numerical model for the aeroelastic problem, combined with optimization techniques, were used to assist in designing feasible mechanical control devices to upgrade the serviceability of this bridge. The performance of the MSDA system is demonstrated through experimental measurements and comparisons of numerical results obtained for time responses of the original and the controlled structure.