A Research On Angular Distortion Rules Of J-Joint Structure After Welding And Welding Sequence Optimization

The topic is to study the welding sequence optimization of the nuclear power structures with J-joints to lower angular distortion. J-joint structures in the nuclear power facilities are widely used. Because of its geometric unsymmetry, the welding leads to the complex distortion rules, the greater angular axial distortion, the coaxial tubes of super-poor, and finally the impact of structural assembly and use. Nuclear facilities with poor working environments, take higher maintenance cost. The facilities need higher precision of the assembly to ensure the operation. It’s meaningful to reduce the welding angular distortion of the J-joint structures to ensure the assembly precision.With the development of computer technology and numerical analysis in recent years, the FEA method for solving complex engineering project analysis is an effective way. The essay through thermal-elastoplastic FEA method simulates the J-joint structure after welding process. The essay first simulates the nuclear J-joint structure with two parameters of joint angleαand joint depth D, to discuss the angular distortion rules of J-joint structure. J-joint structure of the geometric unsymmetry, the pipe and the brick form different angles, and the pipe ramp inserting to the brick easily leads to the trend of inserting direction. Simulation results show that different welding sequences will be corresponding impact on the size and direction of angular distortion. The essay through different welding sequence simulation compares the angular distortion of the tube, to find out the welding sequence with smaller angular distortion, to sum up welding process. Experiment is designed to validate results.