Cause Analysis and Optimization of Subway Vehicles Lateral Stability Exceedance

Objective Rail profile wear and wheel condition degradation during subway operation can lead to changes in the wheel-rail contact relationship, then resulting in obvious abnormal vehicle sway. This not only compromises ride comfort but also poses a latent threat to operational safety. It is necessary to conduct an in-depth research on the causes of stability indicator exceedance and provide a rectification scheme.

Method Potential causes for lateral stability indicators exceedance are analyzed through online test, including system mass and inertial mass, stiffness and damping parameters of suspension components, and wheel-rail contact relationship. The excitation sources and transmission paths of the abnormal sway are systematically clarified. A comprehensive and collaborative rectification scheme is proposed, involving replacing the axle box articulation joints, re-profiling the wheel treads, and grinding the rail profiles, which is then validated through multiple comparative tests of vehicle running stability.

Result & Conclusion  Abnormal vehicle sway stems from wheel-set hunting motion excited by wheel-rail equivalent conicity mismatch, which is transmitted to the vehicle through the bogie frame, causing vehicle lateral stability indicators to exceed the standard. After implementing control measures, the vehicle's lateral sway is effectively suppressed, and the lateral running stability indicators are significantly improved to the excellent standard, thereby verifying the effectiveness of the comprehensive rectification scheme.