Mitigation of post-flutter oscillations in suspension bridges by hysteretic tuned mass dampers

Systems of hysteretic tuned mass dampers are proposed for multi-mode flutter mitigation in long-span suspension bridges. The performance of the nonlinear absorbers is systematically compared with that of classical damped (linearly viscoelastic) absorbers. The equations of motion ensuing from a linearised parametric structural model of a suspension bridge are coupled with the equations governing the dynamics of the passive nonlinear control system and the time-dependent aerodynamic loads obtained through a quasi-steady nonlinear formulation and the unsteady indicial theory. The equations of the controlled aeroelastic system are reduced employing the Faedo-Galerkin method. Numerical simulations are performed to investigate the effectiveness of the vibration absorbers system comparing both the onset of flutter and the post-flutter behavior without the control devices with the corresponding responses obtained when multiple absorbers are installed.