Effect of motor connection on the critical speed of high speed railway vehicles

Considering the specific case of a concentrated power locomotive with motors mounted on the bogie frame, the paper reviews the criteria for nonlinear assessment of vehicle stability based on the simulation of vehicle response to random track irregularity, showing the need for more objective criteria than the ones based on physical testing for vehicle homologation. The effect of elastic motor connection on the bogie frame is examined by linear and nonlinear calculations, which shows that stiffness and damping properties of motor connection have a strong influence on vehicle stability.