Numerical Simulation Of Laser Composite Welding Deformation For Stainless Steel Bolster

Welding technology was widely used in large parts of high-speed trains,for example,traction beams,bolsters,etc.These structures,which included a large number of welded parts,were complex and bulky.Their service performance and product quality were directly affected by residual welding deformation.The prediction and control of welding deformation was an important problem that needs to be overcome urgently in the production of urban rail vehicles for manufacturers.The object of this paper is SUS301L-MT stainless steel subway pillow beam.The SYSWELD simulation software specially developed by the French ESI Group was used to simulate and predict the residual welding deformation of the bolster structure.The main research work of this article includes the following: Firstly,the main five kinds of plug joints were extracted for the bolster structure,and then they were subjected to welding and transient simulation analysis.The actual weld profile and simulated weld appearance were used to verify the heat source model.Secondly,the five main joints were subjected to transient simulation analysis,which was based on a calibrated heat source model,to extract the intrinsic strain value.Finally,the actual welding deformation analysis of the bolster beam was completed.At the same time,the welding deformation analysis of each optimization scheme was completed.They were all based on the inherent strain method.Under the actual process,the simulation analysis shows that: The X-direction contraction deformation was 2.28 mm,and the Y-direction shrinkage deformation value was 0.58 mm,and the X-direction bending deformation amount was 4.66 mm,and the Y-direction bending deformation was 0.61 mm.The simulation results of the X-direction bending deformation and the Y-direction bending deformation were compared with the actual measurement results,and the relative errors were 11.2% and 15.3%,respectively.Comparison of various simulation results leads to the following conclusions.The X-direction bending deformation of the bolster structure and the edge angular deformation of the side panel were 34.1% and 18.2%,respectively,with different rates of constraint.And the X-directional bending deformation of the bolster beam structure and the edge angle deformation of the side upright plate were 18.9% and 22.8%,respectively,with different welding sequence constraints.In the simulation results of various design solutions,the trend of the deformation of the pillow beams was the same as that of the actual welding deformation.The overall structure presented a "concave" in the lower cover plate and a "convex" outward deformation of the upper cover plate.