VIBRATION SUPPRESSION OF TRAIN-INDUCED MULTIPLE RESONANT RESPONSES OF TWO-SPAN CONTINUOUS BRIDGES USING VE DAMPERS

Abstract

This paper presents a study of reducing multiple resonant peaks of high-speed trains traveling over a two-span continuous railway bridge using visco-elastic (VE) dampers. The moving train is modeled as a series of two-degree-of-freedom (2 DOF) moving oscillators with identical intervals and the two-span continuous bridge as a Bernoulli-Euler beam with uniform span. Because of closely spaced frequencies of a continuous beam, the first several frequencies of the bridge would be excited to resonance during the passage of moving trains, which may result in multiple resonant peaks appearing on the response of train-bridge system. In order to reduce the multiple resonant peaks of both the high-speed trains and the two-span continuous bridge, VE dampers are installed at the bottom of the bridge deck to absorb the vibrating energy transmitted from the bridge. From the numerical investigations, the inclusion of VE dampers is useful to simultaneously suppress the multiple resonant peaks of train-bridge system and further improves the riding comfort of moving vehicles. Meanwhile, the strategy of arranging the VE dampers on the continuous bridge is also investigated.