Stress Characteristics And Reliability Research For Standard EMU Body And Equipment Cabin

With the operation of the new generation of high-speed EMU,the "Renaissance EMU",it marks a new step for China's high speed rail technology.As the main bearing part of the EMU,the equipment coMPartment as the foundation for installing other vehicle equipment plays a decisive role in the safety and comfort of the motor train.Based on the standard of EMU(CR400BF)8th vehicles and equipment cabin as the research object,research and analysis mainly rely on line by using the measured data,the main research contents are as follows:1.Based on the finite element simulation and measured data,determined to characterize the body and equipment cabin stress characteristics of 18 stress measuring point are selected as the typical data,divided into 16 level stress spectrum and stress spectrum distribution fitting,the results show that the vehicle and equipment cabin stress spectrum obeys three parameter Weibull distribution.According to the Weibull distribution maximum stress value estimation,expand the compilation of measured data of stress spectrum.2.Based on the measured stress spectrum,using two different theory—Miner theory and Corten-Dolan linear cumulative nonlinear cumulative fatigue theory on vehicle and equipment cabin stress characterization of measuring point were evaluated,measured damage and fatigue life calculation results show that the key parts of the body and equipment cabin can meet the design life of 15 million kilometers,because the Corten-Dolan nonlinear cumulative fatigue theory considering the great influence of stress on the low stress amplitudes,the Miner linear cumulative theory is more conservative;through the operation of cross road damage at different stages of the contribution rate coMParison shows that for most of the measured part speed train contributed most of the damage value,but for some equipment cabin measurement point,the sensitivity for fork and small curve,in the train station and a stage for injury is relatively large.3.Based on a large number of measured data,the dynamic stress analysis of different lines from the angle of time and frequency domain,the results show that the stress level of the big west line is higher than that of the other lines.The characteristics of the three lines in frequency domain are similar,and the frequency domain characteristics of the equipment cabin are very different.The influence of different speed conditions on the car body and the equipment cabin is calculated.Under different acceleration conditions,the stress level of the vehicle and the equipment cabin varies little.However,with the increase of the speed grade,the stress of the point is gradually increased.The change of stress level of measuring point is obvious when 200km/h is raised to 300km/h.4.Statistics under several typical working conditions of the stress characteristics,the results showed that the heavy load for measuring point should not influence the level of force;working conditions for testing stress curve characteristics significantly,the different curve radius,measuring point stress changes;out of the tunnel condition and vehicle operating conditions significantly due to aerodynamic load and air tightness the effect is significant,the vehicle and equipment cabin measuring point stress level increases rapidly,the instantaneous stress amplitude changes.