Structural Fatigue Reliability Research For CRH3A EMU Motor Bogie Frame

Bogie is the main vehicle bearing components, in train running process, steering rack under a load of each random direction changes from, under the long-term effect of random load bearing member from the strain or should be higher local formation damage and accumulated gradually, when the damage reaches a certain level will lead to fatigue failure, is a serious threat to traffic safety. Therefore, it is very important to evaluate the fatigue life and strength of the vehicle bogie. In this paper, through the simulation analysis, bench test and line test run three levels of dynamic stress test of, to CRH3 A EMU framework as the research object, the experimental and simulation results of combining, the framework for the CRH3 A EMU train into action force characteristics analysis and the fatigue strength evaluation. The mainly contents of this thesis are as followed:Firstly, referred on UIC615-4 and EN13749 standard, the gifted and simulated operating under the simulation calculation is carried out of the frame and get large parts are mainly distributed in the lateral beam connection, beam and beam connection and positioning seat angle, gear box hanging seat and beam connection and motor hanging seat is connected with the beam at the site, for subsequent line dynamic force test measuring point arrangement provides the basis.Secondly, calculate the damage of bogie frame respectively according to Miner’s linear cumulative damage theory. The results show the frame satisfied the 12 million safety operation requirement and the life estimated in Miner’s linear cumulative damage theoryThirdly, analyze dynamic stress under different working conditions. With the frequency-speed-energy relation diagram the sources of main frequency energy were detected when the train was in acceleration phase, uniform phase and deceleration phase. Finally the main factors that affect the bogie’s vibration were found out.Fourthly, The stress spectrums were made and the distribution of the spectrums was analyzed, which shows the stress conforms to Weibull distribution. The maximum stress was deduced according to Weibull distribution.