Residual Stress And Deformation’s Simulation On Side Walls Of The Aluminum Alloy High-Speed Train

With the rapid development of high-speed railway in China, the high-speed train speed is continuously increasing. As a result, the production of high-speed train is Corresponding improved in quality requirements. As one important method for manipulating trains, welding can bring about residual stress and deformation which not only affects the beautiful shape of the vehicle, but also causes deviation during body assembly, besides, welding residual stress has significant effects on the fatigue strength. So control of the residual stress and deformation of aluminum alloy welding would be very helpful for the design and manipulating works.The new generation CRH2body adopts thin-walled tubular monologue lightweight aluminum. The materials are A5083P-O, A6N01S-T5, A7N01S-T4and A7N05S-T5series. The body consists of a chassis, side walls and roof. The SYS WELD software was used in this article and simulated the welds on side walls which are made of Ultra-thin large hollow aluminum, and its material is A6N01S-T5aluminum alloy and weld ing method is MIG.Based on the structural of the side wall four types of welding joints was chosen, then the heat sources for each welding joint were simulated and checked and the Gaussian double ellipsoid heat source was determined. The welds on local and whole model were simulated based on the heat source, the distribution laws of residual stress under currently existing welding process was analyzed and the simulation results was compared with the experimental results, the comparison reflected that the simulation results was reliable. After that effect of the welding sequences, heat input on the distribution of residual stress, the conclusions are as follows:First, With the allowed range the residual stress goes down when heat input increases. Second, Symmetrical welding causes minimum residual stress.With the "local-global" method and PAM-ASSAMBLY module, the deformation of the side wall was analyzed, and the effects of heat input, clamping condition and welding sequence were investigated, the results reflected that welding sequence affects the deformation significantly, the deformation increases when heat input increase and clamping can reduce deformation and make the deformation more regular.