Suppression of wind-induced instabilities of a long span bridge by a passive deck-flaps control system: Part II: Numerical simulations

The analysis of the two passive aerodynamic control systems for suppression of the wind induced instabilities of a very long span bridge, proposed in Part I of this study, is presented in this paper. The optimal passive control system configurations are searched on the basis of the proposed performance indices for the system with asymmetric and symmetric cable connection, respectively. The control system with asymmetric cable connection provides large damping and a very high degree of stability in the considered range of wind speed, but requires flaps of large width and large forces to control their motion. The control system with symmetric cable connection provides limited improvement in critical wind speed, but uses small flaps and small control forces.