Dynamic characteristics of high-speed railway vehicle with axle box bearing faults

Based on the motion characteristics of axle box bearings and taking high-speed railway vehicles as the research object, a vertical dynamic model of 17-DOF car body-bogie-axle box bearings-wheel set is proposed. Aiming at the surface fault of axle box bearing, the New-Mark fast numerical integration method is used to simulate and analyze. The dynamic characteristics of railway vehicle under early failure of axle box bearing on inner ring and outer ring raceway surface are studied. The vibration characteristics of axle box bearings under different fault degrees and different vehicle speeds (axle box bearing speed) are analyzed. The changes of vehicle dynamic performance and vibration characteristics under fault evolution are discussed. The analysis results show that the vibration of car body and bogie is little affected by the early fault of axle box bearing; with the deepening of the fault degree, the vertical vibration acceleration and displacement of axle box bearing are increasing; with the increase of vehicle speed, the motion state of axle box bearing undergoes a change from periodic motion, quasi-periodic motion to chaotic motion. Finally, the dynamic simulation results of axle box bearing fault evolution in high-speed vehicle system are validated on the experimental platform. The research work has certain reference value for vehicle condition tracking and monitoring.