Study On Fatigue Performance Of A Subway Bogie Frame

As a kind of low-carbon,environment-friendly and efficient public transportation,subway is an important part of urban transportation network.However,according to the operation of metro vehicles at home and abroad,more and more welding fatigue failures occur,most of which occur in the metro bogie position.The bogie as the travel mechanism of the rail vehicle,once fatigue failure occurs,it will lead to serious safety accidents,so it is necessary to study the fatigue of the welded frame of the subway bogie.This paper takes a domestic subway bogie welded frame as the research object,and uses relevant fatigue assessment standards and methods to assess its fatigue strength,and the specific work is as follows.(1)Based on the structural characteristics of this subway bogie welded frame,combined with the principles of finite element modeling,using hexahedral solid units to establish the frame finite element model;according to the UIC515-4 standard to determine the special load of the welded frame and the main operating load conditions,and the welded frame static strength,vibration characteristics of the analysis,the results show that: the static strength of this frame to meet the expected design requirements,with good vibration quality and Stiffness coordination.(2)To the above analysis,determine the fatigue test simulation of the UIC515-4 standard four load conditions and three loading stages,respectively,based on the IIW standard and BS7608 standard nominal stress method,through the selection of evaluation points,the fatigue strength of the welded frame assessment,and the results of the two standards for comparative analysis,the results show that: the fatigue strength of this frame to meet the design expectations Requirements,BS 7608 standard is more stringent.(3)The equivalent structural stress method was uesd to assess the fatigue strength of the main welds of this frame,and the comparison of the assessment results of the nominal stress method,the results show that: the fatigue strength of this frame also meets the design expectations,but the location of the maximum damage weld occurs is different,compared with the nominal stress method,the equivalent structural stress method is more advantageous and closer to the actual situation.The results show that the equivalent structural stress method is more advantageous than the nominal stress method and is closer to the actual situation.