Performance of multiple tuned mass dampers (MTMDs) for suppressing buffeting response and increasing the critical wind speed of long-span bridges is examined. In this model, each damper is positioned at a distance from the deck center, and corresponding to it, there is an identical damper in the opposite direction to make this system balance. The vertical and torsional dampers are tuned at the frequencies of the first vertical and torsional structural modes, respectively. The performance of vertical dampers is not related to their locations. However, the performance of torsional dampers is strongly dependent upon their lever arms to provide torsional damping and stiffness. Using both vertical and torsional dampers, the vertical and torsional buffeting responses can be reduced and the stability of the bridge can be increased for either single-degree-freedom flutter or coupled flutter. A parametric analysis is used to study the performance and characteristics of the MTMDs, and based on these results, the design parameters including mass, damping, frequency bandwidth, lever arm, and total number of TMDs are proposed. The results also indicate that the MTMDs, designed with the recommended parameters, are not only more effective but also more robust than the usual single TMD against windinduced vibration.
關聯:
Journal of the Chinese Institute of Engineers=中國工程學刊 24(3), pp.273-288
