Abstract: Welding is the most widely used connection mode in the assembly process of the electric multiple unit (EMU) while the deformation induced by welding will have a great influence on the assembly precision. The influence of welding deformation on the assembly precision of the sidewall window module is discussed in this paper. Firstly, the inherent strain of three typical welded joints in the sidewall window module of the EMU is extracted by the thermal elastic-plastic finite element method. Then, the deformation of the sidewall window module is obtained by the finite element simulation based on the inherent strain method. The obtained deformation is considered as a mean shift to amend the 3D assembly variation simulation results of the window module. Finally, the amended simulation results are compared with the measured data. The simulation results of assembly variation considering welding deformation have a good agreement with the actual measured data which indicates that the proposed method is more accurate and feasible for predicting the assembly variation of the sidewall window module of the EMU.

Key words: welding deformation, inherent strain method, finite element simulation, assembly variation simulation, electric multiple unit (EMU)