Numerical Simulation And Application Of Temperature And Stress-strain Of Space Curves Welding

Welding technology is widely used in the modern industrial production, the welding process is accompanied by local temperature and uneven heating. Welding residual stress and deformation of parts in the melting area and the solid state seriously affect the fatigue strength and service life of the weldment, so grasping the temperature control and the distribution of stress and strain fields during the welding process for the actual welding quality assurance is particularly important.In this paper, we firstly use the finite element method based on SYSWELD software platform and use the double ellipsoidal heat source distribution model. This paper simulate the distribution of temperature field and the stress and strain fields of the T-shaped pipe in welding process. Combined with the existing laboratory equipments, we used infrared thermal imager to detect the real-time temperature distribution during the welding process, processed the data of test results. Then compared with analysis results to verify it; combined with validation data to optimize the process of the simulation analysis, in this way we can reach the guiding significance for the actual welding which can match the experimental results of the analysis process with e simulation analysis.Based on this type of analysis processes to simulate the pipeline transportation elbow flange welding. The maximum temperature in the temperature field is around 1630℃ and the analysis is consistent with previous results. In the 300 s moments, stress is within the scope of its tensile strength(490-695Mpa), maximum strain is 0.32 mm,but the overall excursion appearing at the elbow whose offset is 0.29 mm affects the subsequent installation process and elbow flange 90° vertical degree; therefore, on the basis of the conditions, optimizing chucking and imposed the chucking conditions to prevent rigid body motion at the elbow; re-analysis the overall and obtain maximum strain 0.29 mm, strain around the bend at the end face down to 0.1mm which greatly ensure the size requirements of the elbow,being ready for the subsequent installation. This analysis method can effectively reflect the temperature of the welding process and distribution of stress and strain fields, can ensure the welding quality by changing the welding path and optimize the process parameters. This method has the advantage of greatly reducing the welding test cycle, saving the cost of experiments, for pipe installation in the welding process play a guiding significance.