Numerical Simulation for Welding Sequence Optimization of Gymnastic Bicycle Frame

The welding finite element model of the gymnastic bicycle frame was built using shell elements instead of solid elements by software MARC. The errors between the simulation by shell elements and by solid elements were analyzed and the correct coefficient of 1.136 7 was obtained. The welding simulation by two welding schemes in twelve sequences of the five welds of the frame was conducted. The main welding deformation of the frame was analyzed, the welding sequence was optimized and verified by experiments. The results show that the deflection of the cushion tube was the main welding deformation of the frame. The deflections of the cushion tube after discontinuous welding in different sequences were lower than those after continuous welding. The optimal welding sequence was discontinuous welding in the order of the girth weld of anterior inclined tube and cushion tube, inner side weld of anterior inclined tube and locating plate, lateral weld of cushion tube and locating plate, inner side weld of cushion tube and locating plate, lateral weld of anterior inclined tube and locating plate. The simulated deflection values of the cushion tube after discontinuous welding in different sequences coincided well with the measured results, proving the accuracy of the finite element model.