Influence Of Mass Distribution On Vehicle Dynamics Of High-speed Railway

The rapid development of high-speed train technology in China has led to increasing attention to the lightweight and high-speed design of vehicles.How to reduce the quality of high-speed trains while ensuring their safety,smoothness,and stability,in order to improve performance and reduce energy consumption,is a problem worth studying.This thesis mainly studies the influence of Mass distribution characteristics on the dynamic performance of high-speed trains by means of dynamic simulation,in order to find the best Mass distribution law and provide a reference for the dynamic design of high-speed railway vehicles.The main research content of this thesis is as follows:(1)Taking a certain type of 380 km EMU vehicle in China as the research object,a parametric model of high-speed railway vehicle dynamics is established by using the multi-body dynamics software UM(Universal Mechanism).The effectiveness of the model is verified through simulation and dynamic performance analysis.(2)The influence of mass parameters of vehicle frame,wheel set,motor and other components on vehicle dynamics performance is studied.When the vehicle operates at a speed of 300 km/h,the mass change of the wheel set has the greatest impact on the dynamic performance indicators,followed by the impact of components such as the frame and motor.Through orthogonal experimental design analysis,when the mass of the wheel set,frame,and motor decreases,the safety,smoothness,and stability of the vehicle are improved,and all are within the range specified in the national standard.(3)The influence of vehicle mass parameters on vehicle dynamics performance under the conditions of no load,full load uniform distribution,left and right bias loads,front and rear bias loads and diagonal bias loads is studied.The results show that the unbalanced load will worsen the vehicle dynamics performance indexes,and the diagonal unbalanced load will worsen the most.When the weight of the vehicle body is reduced by less than 40% under the condition of front and rear eccentric loads,all dynamic indicators are within the range of national standard requirements.However,when there are left and right and diagonal eccentric loads,they do not meet the requirements of all dynamic indicators.(4)Based on the vehicle dynamics model,a parametric joint simulation model is established using UM/CoSimulation and Matlab/Simulink.The Mass distribution of car body,frame and wheel set is optimized by genetic optimization algorithm with the objective of vehicle lightweight and dynamic performance respectively.The results indicate that,while meeting the minimum requirements of the national standard,lightweight design can reduce the existing vehicle body,frame,and wheelset masses by 32%,90%,and 90%,respectively.However,compared to before optimization,the wheel load reduction rate deteriorates by about 20%,and the lateral stability index deteriorates by about 8%.When optimizing for dynamic performance,the mass of the wheel set and frame decreases by 90%,but the mass of the vehicle body increases by18%.At this time,the optimal ratio of the vehicle body,wheel set,and frame is approximately 800:4:3.The influence of Mass distribution characteristics of high-speed railway vehicles on vehicle dynamics is studied by using dynamic simulation method.The research method can provide theoretical support for lightweight design of high-speed trains,and the research results also have certain application value.