Stability of a Railway Vehicle with Bouncing and Pitching Motions on a Multispan Simply Supported Girder System : 2nd Report, Stability analysis and Simulation of Vehicle Behavior

The dynamic behavior of parametrically excited vibration of a railway vehicle on a multispan simply supported girder and characteristics of girder to influence on the stability of railway vehicle were found in this paper, following previous study. A simplified mechanical model of the Shinkansen vehicle and an actual girder and some model girders of the railway bridge, which had the same flexural rigidity as the the girders of the old line in Japanese National Railways and the same distance between the main girders of bridge as the Shinkansen, were used in this investigation. It was found from the analytical results of stability that lowering of the flexural rigidity of girder caused the unstable regions in the stability map to broaden, especially the flexural rigidity affected to the unstable vibration of the track, and use of the shorter span girders than 20m long was advisable for the Shinkansen vehicle. Moreover, It was found from the results of simulation that the amplitude of railway vehicle in the simple parametric resonance was smaller than the amplitude in the resonance due to the forced vibration.