Finite Element Analysis Of The Welding Temperature Profiles And Thermal Distortion In DE-GMAW

Double-Electrode Gas Metal Arc Welding (DE-GMAW) is a novel arc welding process with high efficiency. In DE-GMAW, the MAG arc is the main arc while the TIG arc is a bypass arc. Because the TIG arc takes away some current, the current flowed on the base metal is decreased based on the premise that the total current is constant. Thus, the deposition rate can be guaranteed and the heat input to the base metal is reduced. The high deposition rate and high speed welding could be realized in DE-GMAW. In this study, the numerical analysis model of the DE-GMAW process is developed with considering its characteristics. And the model could be the basis for optimizing the parameter of the new welding process.The functions of the software SYSWELD are extended. A simplified method for processing the weld reinforcement is put forward. The "dead-actived elements" technique and different mesh plotting are employed to consider the deformation of the weld pool surface under the action of the arc pressure, molten droplet impact and so on. A 2-D Gaussian heat source and a volumetric heat source are combined together to simulate the heat input as a composite heat source. A finite element analysis (FEA) model for DE-GMAW is developed which is used to make numerical simulations of the temperature distribution during DE-GMAW. The results show that the predicted weld dimensions at cross sections match with the experiment ones.When the total current flowing the wire (I) is constant, for MIG welding, the bypass current flowing the TIG torch (I_bp) is zero, while for DE-GMAW, I consists of two parts (the bypass current I_bp and the base metal current I_bm) , and I_b is non-zero. For the study case 1 of DE-GMAW, I=330A, I_bp=80A and I_bm=250A. For the study case 2 of MIG, I-330A, I_bp=0A and I_bm=330A. The numerical analysis of temperature...