OPTIMUM DESIGN OF TUNED MASS DAMPER FOR FOOTBRIDGE

With the trend towards more lighter and slender footbridges, the vibration serviceability is more critical in design. The tuned mass damper (TMD) has shown a high efficiency in reducing the excessive vibrations under dynamic loads induced by pedestrians. Based on the distributed parameter method, a general measure to calculate the dynamic response of a footbridge-STMD system or a footbridge-MTMD system is suggested. The efficacy of TMD in controlling footbridge vibration under walking loads is examined according to the root-mean-square acceleration, and the optimal placement and parameters of a TMD system are discussed. The proposed method is also verified by numerical examples.