Running Stability Analysis of Bogie for Gauge Changing Train

Abstract

Gauge changing train is developed to realize through operation between standard gauge and narrow gauge. Axle of gauge changing train has lower torsional stiffness than solid wheelset or has clearances inside. Although running stability and safety at the target speed (270 km/h) have been validated through bench tests and on-track tests, theoretical investigations have only been carried out for limited conditions. This paper performs numerical simulations using simplified half-car model of gauge changing train at standard gauge mode and evaluates the influence of torsional stiffness or longitudinal and rotational clearance on running stability. Simulation result shows that low torsional stiffness has little effect on running stability. Longitudinal clearance causes small amplitude continuous vibration, whose wavelength is between axle and bogie hunting wavelength. Rotational clearance causes large amplitude, low frequency continuous vibration only if there is no friction on the rotational clearance. This low frequency continuous vibration is not the bogie hunting but a vibration mode of entire half-car system. For gauge changing train with improved axle (called “Type II” in this paper), critical speed of hunting is a little lower compared with the train with solid wheelset, but enough safety margin is secured.