Investigation on Load Definition of Vibration Fatigue of Railway Vehicle Bogie
The load is the fundamental input for the fatigue-resistant design of railway vehicle bogies.Understanding the definition method of standard loads and elaborating the differences between standard loads and service loads is of great significant importance for the fatigue-resistant design of railway vehicle bogies.The main characteristics and causal factors of vibration fatigue of bogie system,as well as the countermeasures,are primarily reviewed.The load definition methods of standard loads are explained from the vehicle system dynamics point of view,and a method is developed to convert the random loading spectrum to three-levels loading spectrum,which further facilitate to study the applicability and safety margin of bounce and roll factors for China high-speed railway.Regarding to the vibration spectrum of bogie components,the difference between the standard and measured vibration spectrum is discussed.The results show that the most failure cases occurred at the sub-components of railway bogie,the structural resonance caused by high frequency wheel-rail vibration serves as the main cause of vibration fatigue failure of bogie components.Compared with the actual service conditions,the bounce coefficient of vehicle given in standard has a higher safety margin,and the rolling coefficient is significantly affected by the vehicle stability.The vibration spectrum of axle box defined in the standard underestimates the vibration level in the high frequency range.Therefore,according to the characteristics of wheel-rail coupling vibration,the characteristic frequency band of axle box is defined,and a flat vibration spectrum of axle box considering multi-characteristic frequency band of wheel/rail is proposed.The discussions of loading definition for bogie system given could serve as an important reference for the vibration fatigue design of railway vehicles.
rail vehiclebogie systemvibration fatigueloading coefficient of fatiguevibration spectrum of axle box
万方数据
维普
