Bridge Flutter Prediction and Active Control Using Modal Information and Flutter Margins

In this paper, a flutter prediction method based on flutter margins is proposed for streamlined bridges whose aeroelastic behavior can be well approximated by a two‐degree‐of‐freedom (2‐DoF) flutter model. The method enables prediction of the flutter boundary by extrapolating a curve of flutter margin versus wind speed, constructed using flutter margins at several subcritical wind speeds. In addition, an ‐optimal flutter active control method based on measured receptances and flutter margins is proposed. It enables assignment of the flutter boundary to a prescribed wind speed value or range for each considered angle of attack (AoA), while simultaneously minimizing vibration responses at subcritical wind speeds, using a single controller with optimal control effort. Hence, the designed controller is robust to the variations of wind speed and AoA. The proposed flutter prediction and control methods require only a small number of systems’ modal parameters or open‐loop receptances at several subcritical wind speeds. The proposed flutter prediction method typically requires fewer system modal parameters than existing methods that track the variation of damping ratio against wind speed. The proposed flutter suppression method avoids some modeling errors associated with conventional system matrix‐based methods. The working of the proposed flutter prediction and control methods are validated using wind tunnel tests and CFD simulations, respectively.