Sensitivity analysis on dynamic response of railway vehicle and ride index over curved bridges

摘要

When a train passes over bridges, the magnitude of forces and accelerations is altered due to sudden changes in the track stiffness. These forces can change with the variation in operational parameters and are effective particularly in high-speed passenger trains, when studying ride index parameter. In addition, by increasing the speed, old bridge structures could fall into resonance, which has harmful consequences for both bridge and ride comfort index. Moreover, to harmonize the old bridges with the new operational conditions dynamic behavior of the vehicle and ride comfort need to be taken into account. In this paper, coupled vertical and roll vibration of a horizontally curved bridge are considered. During pass over the bridge, acceleration and ride comfort of a passenger vehicle are studied. The eccentric vertical and lateral forces are the major excitation sources in the analysis, an issue that is rarely noticed in the literature. A multi-body model of a normal wagon is built in three dimensions, passing over a horizontally curved bridge. The governing equations of the vehicle-bridge system are written, taking into account the wheel-rail interactions. The major variables are the cant, train speed, track quality, and radius of curvature. The paper studies the effects of the prescribed variables on ride comfort. The results show that track quality and cant have considerable influences on ride comfort index. The ride comfort is improved when the speed is approached to a so-called equivalent speed.