High-speed Emu Aluminum Elloy Weld Fatigue Life Prediction Of Vehicle

As a high-speed rail transport, the technology of EMU has got a great development. In order to adapt to the increasing number of passengers, the speed of China’s high-speed EMU has been raised several times. Meanwhile, accidents caused by fatigue and fracture of the rail vehicle occur frequently, in order to ensure the safety and reliability of high-speed EMU operation, the research of fatigue has become the urgent problem of the transport.CRH3EMU, as the research object in this paper, firstly, the finite element model for fatigue strength analysis is established. According to EN12663-2010standard, seven fatigue analysis cases are determined, For analysis of the fatigue strength of the vehicle body,ANSYS software is used to calculate the maximum principal stress of the body in all cases. Then, infinite life design method is used for the prediction of the body fatigue life.Secondly, the main S-N curve method based on ASME standard is taken to predict fatigue life of the265welds of the vehicle body. In this paper, by using FE-WELD software,17welds are chosen as the example for evaluation of stress analysis and weld structure stress are obtained of the seven cases. Then, choose98%reliability-2σ main S-N curve to predict the weld concentration stress analysis and fatigue life. The result satisfies the standard requirement that the life times are more than107times. In this method, the main S-N curve model is used to predict the fatigue life of the weld which can’t be influenced by the form of welded joints and load cases, therefore, the mesh sensitivity problems and uncertain calculation results in IIW and BS standards can be solved perfectly. Compared with the infinite life design method,the main S-N curve method based on ASME standard can be proved as a better way.Finally, considering the character of the complexed structure of the high-speed trains, the large amount of welded joints and fatigue performance prediction datas,"High-speed trains aluminum alloy body typical weld joint fatigue performance database system" is established and the high-speed trains aluminum alloy body welded joints fatigue prediction database management based on three-dimensional visualization is builded.