| The bogie is key component to ensure the the quality of operation,dynamic performance and traffic safety of metro vehicles.The frame is complicated welded structure,which is an important component part of the bogie.There are many welding lines in the joint of beam and side frame and other areas.If residual stress generated in welding process superimposes the peak stress of external load in the same location,the safety and lifetime of metro vehicles willed be iMPacted.Therefore,when assessing the strength of welded structures,we must consider the iMPact of welding residual stress.Welding speed and constraint condition have a significant effect on the residual stress.The workload of obtaining optimum welding process by means of conventional experimental methods is huge and impractical.Numerical simulation based on finite element software can optimize the welding parameters and control the quality of welding.In this paper,the numerical simulation of welding process by means of finite element software SYSWELD is of great significance.This paper studies collaborative design method for welded frame of metro bogie. First of all, according to the standard "UIC615-4" and "EN13749" and referring to design parameters provided by factory technicians, determine service loads for welded frame of metro line1.Calculate stress distribution of key parts of the frame without residual stress based on finite element analysis software ANSYS.Then,simulate temperature field and stress field distribution of girth weld in the jiont of beam and side frame under three welding speed and constraint conditions taking advantage of welding numerical simulation software SYSWELD.Finally,convert the format of residual stress results file in three welding speeds and import it into ANSYS as the initial load,and couple it with the service loads respectively.Study stress distribution of key parts of the frame and assess the strength of frame.It turned out that the weak position of the frame changes when considering welding residual stress.The strength falls significantly after stress superposition in the area where security strength is large originally.Therefore,in the strength design of the welded structure,we need to consider the matching process and cooperate both of two to obtain optimal structures and processes. |
