This work presents an improved model of characteristic equations for gas metal arc welding process. In this paper, a dynamic electrical model is introduced as a rectifier power source instead of pervious common simple models. In addition, an electrical resistance model is proposed for bridge in short circuit period to consider the effect of melting temperature and variation of the conducting area. Furthermore, the arc length equation during the arc period is modified considering the size of the cross zone between the arc and drop. Finally, the introduced modifications are simulated and compared with the experimental results.
