Study On The High Speed EMU Motion Stability Based On Wheelset Equivalent Conicity

The stable operation of the train is related to people’s life and property safety. The running stability of the vehicle is one of the key factors affecting the safe operation of trains. Accompanied by China’s high speed railway passenger line openning and operating after another, under the background of constantly refreshing the highest speed in the test operation of trains and the continuous increasing of operation speed, study on the motion stability of high-speed EMU will be particularly important.The wheel-rail contact geometry plays a bridge role in the whole vehicle-rail system. The traction, braking and steering and other basic functions of railway vehicles is realized by rolling contact of wheel and rail. The wheelset equivalent conicity is one of the decisive parameters of wheel-rail geometrical contact and the core factor of wheel-rail matching, and it has a direct relationshio of the wheel-rail dynamic interaction, surface wear and traction play etc.Therefore, it is of great realistic importance to do the research of the wheelset equivalent conicity on the high-speed EMU motion stability and also to provide theoretical basis and technical support on the structure design of high speed train and EMU Operation and maintenance.This paper introduces the background and significance of the topic, and analyzes the research status at home and abroad firstly. According to the basic principle of multi-body system dynamics, the model hypothesis and nonlinear processing and so on, using multi-body system dynamics simulation software SIMPACK established vehicle dynamics model of a high speed EMU. Then introduces the research method of vehicle motion stability and related theoretical basis.This paper focuses on the specific impact of wheelset equivalent conicity on the stability of vehicle system. The research results show that:for the two route spectrum excitations, the change trend of the equivalent conicity influence on the stability of the running vehicle system is consistent under the condition of linearization and the actual-wheelset surface wear, the wheelset equivalent conicity has a direct great impact on the running stability of vehicle system; With the increase of the wheelset equivalent conicity, the critical velocity under different standards are showing a downward trend. According to the analysis results, the use of frame lateral acceleration amplitude method as the evaluation standard of running stability of vehicle system is rcommended. For this high speed EMU, under the condition of China’s the Beijing-Tianjin Intercity Railway measured route spectrum excitation, when continuous operating speed speed is 330km/h,0.27 can be used as the limit value of the equivalent conicity; when continuous operating speed is 350km/h,0.23 can be used as the limit value of the equivalent conicity.In addition, it is suggested to combine with the measurement of wheelset equivalent conicity to make the wheel lathing repair cycle, which can effectively avoid the occurrence of transverse vibration alarm phenomenon of High-speed Rail vehicle, which can better ensure the safe operation of High-speed Rail vehicles.