Research On Structural Fatigue Of High Speed EMU Power Bogie Frame

In order to meet the increasing needs of our country,the speed of trains is constantly increasing,and the reliability of trains is facing greater challenges.The bogie between the train body and the wheelset is only supported by the bogie.The safety and reliability of its structure directly determines the safety of the train.All the structures in the bogie rely on the support and load of the frame,so the load it receives is very complicated Fatigue cracks are prone to occur,resulting in unreliable driving safety and reliability.Especially under the condition of high-speed and high-frequency working conditions of the high-speed train frame,the fatigue reliability requirements of the frame are higher,which will also affect the maximum safe driving speed of the high-speed train in practical applications.Therefore,it is necessary to research the fatigue strength of high-speed EMU bogies.The thesis mainly carries out the following research work:In accordance with the drawings by using 3 d software Pro-e structure 3 d model is set up,on the basis of the basic theory of finite element,structure characteristic and the material properties,structure finite element model is established based on ANSYS Workbench,in accordance with the international union of railway standards UIC 615-4 and EN 13749 as a strength test standard requirements,calculate the frame corresponding conditions of load,and using the Workbench software simulation to static strength analysis framework.According to the basic theory of multi-body dynamics,structure parameters and dynamic parameters,the multi-rigid body dynamics model of the vehicle and the rigid-flexible coupling dynamic model of the vehicle with the frame as the flexible body were established based on UM software.The dynamic responses of the two types of frames in time domain and frequency domain were simulated in UM,and the differences in dynamic parameters of the two types of frames were compared.Based on the above analysis results,a more realistic rigid-flexible coupling dynamic model is adopted to solve the vertical load spectrum of the air spring and the transverse load spectrum of the transverse stop of the frame.The basic theory and method of fatigue analysis are introduced.Goodman fatigue limit diagram is used to evaluate the fatigue strength of static simulation analysis.Based on n Code DesignLife joint simulation and palmgren-miner theory,the load mapping was set up to obtain the cloud map of fatigue life and fatigue damage,so as to intuitively understand the overall fatigue condition and weak parts of the framework.The results of calculation and analysis show that the analyzed framework meets the strength standard of UIC615-4 and can meet the requirements of safe and reliable operation during the maintenance cycle.