Key Parts Of High-speed Train Alloy Body Weldeing Aluminum Numerical Simulation

With the rapid development of high-speed railway in China, manufacturing and processing quality of high-speed trains is also put forward higher requirements. In order to achieve the purpose of weight reduction, aluminum alloy is widely used in the body structure, in the process of the vehicle body, welding is an essential measure. Aluminum welding technology is one of the key high-speed train manufacturing process technology. Since the welding process is partial heating and subsequently cooled rapidly, So inevitably produce residual stress in welded joints. So reduce welding residual stress is a outstanding problems during welding aluminum alloy body of high-speed train. The generated rule of Welding temperature field and welding residual stresses are researched by using numerical simulation simulate welding process; And then formulate a reasonable welding process, to achieve the purpose of reducing the welding residual stress, Meet the railway vehicles of high performance, high standards.Firstly, based on the three-dimensional thermal elastic-plastic theory, detailed analysis features and mathematical expressions of Gaussian heat source model,3D Gaussian heat source model, Cylindrical heat source model, Double ellipsoid heat source model; adjust double ellipsoid heat source model appropriate for the numerical analysis of high-speed trains sidewall. By comparing the molten pool result of numerical simulation with the actual cross-sectional shape when reaching quasi-steady state, it shows that the SYSWELD simulation result is consistent with experimental result.Secondly, Numerical simulation of temperature field side wall of high speed train CRH380B, get the distribution of different time side wall welding temperature field. Gain characteristics over time of perpendicular to lateral weld area and Direction along the weld centerline node temperature.Finally, numerical simulating the effects of different welding sequence to sidewall stress field, and ultimately get the optimal welding sequence program; simulation analysis high-speed trains of the middle car underframe KK end multi-pass welding, and get the welding residual stress distribution. At the same time, analysis the impact of subsection welding on welding residual stress distribution, by comparing simulation results, draw the conclusion that the subsection welding can effectively decrease the welding residual stress of the KK-end.