ABSTRACT
Hydraulic dampers were broadly used in the seismic design of structures, especially in those long span cable-stayed bridges. However, the practical performance of those dampers is quite difficult to acquire and predict. Aiming to understand the damping performance of dampers of Sutong bridge, an experimental method based on vibration testing was proposed in this paper. Firstly, dynamic response numerical simulation of a SDOF model under random excitation with lower frequency about 0.065Hz and higher damping property were carried out. A damping ratio identification method was proposed and verified based on simulated random acceleration output. Then, field testing was performed, and several acceleration gauges were mounted on the bridge. The longitudinal vibrations were gathered, and the damping ratio had been identified four times during the past two years. The results show that the overall damping ratio of those large-scale hydraulic dampers kept in the relatively constant level, which reveals that the performance of those dampers was in a relatively good condition.
