NUMERICAL SIMULATION OF THE WELDING PROCESS - DISTORTION AND RESIDUAL STRESS PREDICTION, HEAT SOURCE MODEL DETERMINATION

摘要

The paper presents the results of our recent developments. Studies for detailed understanding of the behaviour of a steel structure during welding operations have been carried out. Mainly the distortion of the steel structure has been observed. Several welding experiments have been prepared and carried out. The results from the welding experiments have been used as the input and output parameters during the numerical simulations. Measurements were also carried out on the material properties needed for numerical analysis. Numerical simulations have been made according to experiments. The calculated results were compared with the measured results. Based on the comparison parameters have been determined, which have an influence on the final distortion of the steel structure. The following input parameters have been observed: model of the temperature source, constraint condition, and material models. A good correlation has been obtained for temperature (mainly for shape and size of the molten zone) as well as distortion prediction between experimental and numerical approaches. The double ellipsoid heat source model has been used and modified to fit the measured parameters. The modified double ellipsoid heat source was used for MMAW and GTAW welding technology.