Analysis Of Load-Carrying Capacity Of Welded Bogie Frame Based On Non-liner Finite Element Method And Design Of Ultrasonic Detection System

The rapid development of high-speed railway in China calls for a new requirement of the safety of high-speed train. The bogie frame, which is welded together, is the most important component in a high-speed train. In the welding process, the welding residual stress and welding defects are formed, which will certainly affect the load-carrying capacity of welded bogie frame. Therefore, it is quite important to study how the welding residual stress and welding defects affect the load-carrying capacity of the welded bogie frame.Based on the finite element software ANSYS, a type of welded bogie frame is studied. Four local structures of the bogie frame have been welding simulated and analyzed based on the thermo-mechanical coupled finite element method. Furthermore, the affection of the welding residual stress and welding defects on the load-carrying capacity of welded bogie frame has also been analyzed. At last, an ultrasonic detection platform for welding defects are designed and debugged.Firstly, the finite element model of the welded bogie frame is set up, and then it is analyzed according to the UIC515 norms of International Union of Railways. Some local structures with larger average stress and stress amplitude of the bogie frame are obtained.Secondly, the finite element models of those local structures are set up and welding simulated based on the thermo-mechanical coupled finite element method to get the distribution trend of the welding residual stress on those local structures. According to the result of simulation, the cause of how welding residual stress affect the load-carrying capacity of welded bogie frame is studied. The ultimate bearing of the local structures with the welding residual stress is calculated based on the theory of ultimate bearing of elastic-plastic structural.Furthermore, the mathematical models of the empty type of weld defects are set up, the impact of different shapes and location of the welding defects, whose standard is the stress concentration factor, on the load-carrying capacity of welded bogie frame is then studied.In the end, the ultrasonic detection platform for welding defects is discussed and designed; also the hardware debugging is carried out.