Deformation simulation and welding sequence optimization for multi-pass girth welding of bogie frame

Based on the analysis of welding-induced deformation mechanism,a finite element model is estabilished for a welded railway bogie frame to simulate the multi-pass girth welding-induced deformation by combining solid and shell elements,and shell elements are employed to realize the transition between 3D and 2D elements to avoid the divergence resulted from the rigid link.A volumetric heat source defined by double ellipsoid is adopted to simulate the thermal distribution during the welding process.The mean thermal cycle curves are extracted and simplified based on the heat source fitting results to improve the computational efficiency.Then,the multi-pass girth welding deformation of the bogie frame is simulated and the optimization of the welding sequence is achieved for the deformation control.The results indicate that the proposed methods are feasible for simulating the multi-pass welding-induced deformation of the large welded structures.