High accuracy Numerical simulation on 3D weld-pool shape of large parts

Abstract

The shape of weld pool and the distribution function of heat source are the premise and foundation of all welding simulations, but many assumptions are given to them which lead to different or even contradictory results. So the model of three-dimensional weld pool should be established without predetermining the shape of weld pool, the shape of free surface and the distribution of heat flux density, moreover it is combined with the thermal model. Through decoupling, the fluid velocity field, the temperature contour and the law of temperature distribution of the weld pool are obtained, the shape of molten pool is also gotten out which is like a revolving body of the pen holder, and the density function of heat flux distribution is fitted out. The internal relationship between simulation results and weld fusion line are presented. Welding experiments of large parts are carried out under the same process conditions. It shows the weld fusion line and the shape of the surface of the weld are in good agreement with the simulation results. This has great practical significance for unifying simulation results, guiding production and improving quality of large welding parts.