动车组转向架横向止挡座焊接工艺仿真研究

Simulation on Welding Process for Transverse Stop Seat of EMU/DMU Bogie

为了快速确定铁路动车组转向架上尺寸较小、焊接结构复杂部件的焊接工艺,选取某动车组横向止挡座焊接工艺为研究对象,预设2种定位焊工艺和2种组焊顺序,形成4种焊接工艺方案。采用有限元分析软件,对动车组横向止挡座的4种焊接工艺方案进行仿真对比分析。仿真结果表明:横向止挡座采用不同的定位焊工艺对焊接应力和变形的影响较小,适当减少定位焊缝数量对实际焊接生产更有意义;横向止挡座采用“下盖板中间焊缝—下盖板两侧焊缝—立板中间焊缝”的组焊顺序相对更合理。工装刚性固定的压卡方案能够将焊接变形控制在1 mm以内,但局部焊接残余应力峰值为500 MPa,实测焊接残余应力峰值出现在焊缝中心线处,为325 MPa;采取抛丸处理工艺,可以将残余应力降至-327 MPa,达到削减较高焊后残余拉应力的目的。

In order to rapidly determine the welding process for the components with small size and complex welding structure on the EMU/DMU bogie,the welding process of the transverse stop seat of a certain EMU/DMU is selected as the research object,and two positioning welding processes and two assembly welding sequences are preset.It consists of four kinds of welding process schemes.The finite element analysis software is used to simulate and compare the four assembly welding schemes of the transverse stopper of the EMU/DMU.The simulation results show that the different t positioning welding processes has little effect on welding stress and deformation of the lateral stop seat,and it is more meaningful to reduce the number of positioning welding appropriately for actual welding production;It is relatively reasonable to adopt the welding sequence of"the middle weld seam of the lower cover plate of the transverse stopper seat-the weld seam of both sides of the lower cover plate of the transverse stopper seat-the middle weld seam of the vertical plate of the transverse stopper seat".The clamping scheme with rigid fixation of the tooling can control the welding deformation within 1 mm,but the peak value of the local welding residual stress reaches about 500 MPa.The actual peak value of residual stress is 325 MPa at the center line of the weld.The residual stress of the lateral stop seat is reduced to-327 MPa by shot peening treatmeng processe,which can achieve the purpose of reducing the high welding residual tensile stress.