Suppression of flutter and gust response of bridges using actively controlled edge surfaces

Control surfaces at the edge of a bridge deck are proposed for flutter suppression and gust alleviation. The state-space equation of motion is derived considering the aerodynamic and dynamic interaction between the deck and the control surfaces. Unsteady aerodynamic forces are included in the equation of motion using the rational function approximation. The derived equation combined with the output feedback optimal control theory, is adopted. Based on the numerical example for a three-dimensional bridge, it is found that the proposed method can sustain stability within the design wind velocity, and reduce gust response as well. Furthermore, it is found that multiple controllers distributed in the center span do not lose its stability abruptly, even if some of controllers do not operate.