The Performance Analysis And Optimization Of High-speed EMU Bogie Frame

With the continuous improvement of the speed of high-speed EMUs,the problems faced by vehicles in operation are also increasing,and the safety of train operation has become particularly important.As a key component of the high-speed EMU bogie,the frame plays a major bearing role,and its performance directly affects the running quality of the EMU.This subject takes a certain type of high-speed EMU power bogie welding frame as the research object,analyzes the performance of the frame,and optimizes its design under the condition that the strength meets the requirements.First,use the Hyper Mesh software to mesh the frame,and obtain the finite element model of the welded frame with shell elements as the main body;secondly,use the ANSYS software to perform modal analysis on the frame under unconstrained conditions,and then use the Hyper View software to process the results,The seventh to thirteenth order modal frequencies and mode shapes of the frame are obtained.The results show that the frequency of each order of the frame is within a reasonable range;then,the static strength analysis of the frame is carried out according to the UIC 615-4 standard,and the frame is obtained.The maximum Von.Mises stress and stress cloud diagram under two abnormal load conditions and thirteen simulated operating load conditions,and the calculation results are checked according to the fourth strength theory,and the safety factor of each dangerous point is obtained.The results show that the safety factor of the frame under all working conditions is greater than 1,therefore,the static strength of the frame meets the requirements;after that,a number of base materials and weld evaluation points are selected under fatigue conditions,and the Goodman curve diagram method is used first The base metal and weld evaluation points are evaluated for fatigue strength.Then,the same points are checked using the IIW standard,and then the master S-N curve method(equivalent structural stress method)in the ASME standard is used to evaluate the weld evaluation points.,The results show that: the fatigue resistance of the structure meets the requirements,and then based on the comparison and analysis of the obtained results,the differences of several methods are obtained;finally,when the strength of the structure meets the requirements,the smallest volume is the design goal,with the help of Opti Struct software The size of the welded frame was optimized,and the optimized model reduced the weight by 7.34% compared with the original structure.Through the research of this subject,the performance characteristics of the high-speed EMU bogie frame and the differences in the use of the Goodman graph method,the IIW standard and the master S-N curve method can be obtained,which provides a reference for the future selection of the fatigue assessment standard of the bogie frame.The result of the optimized design provides a solution for the weight reduction and lightening of the bogie frame in the future.