Welding is widely used in different fields of industry such as space and aeronautics, ship-building, bridge building and machine building. The welding process causes an uneven distribution of heat, which makes thermal strains and local plastic deformations. Welding induced residual stresses and distortions cause important problems such as failure, or reduction of buckling strength of the structure[1]. In order to further develop the welding technology it’s necessary to gain better understandings in the complicated phenomena of thermodynamics during welding. One way to gain such a deep and optimized understanding is to use computational simulations. In this research first we consider the different mathematical models of heat source which have been used in simulation of welding process more frequently, and then study the result of coupled and uncoupled thermo-mechanical simulation, and after all compare the simulation results with the experiment. In this article we have used a new technique in 3D simulation of welding process which can predict the effects of welding process in an acceptable range. Herein the effect of using coupled or uncoupled thermo-structural approaches in welding simulation is studied. All analysis is performed in ABAQUS code.
