Dynamic behavior of GMAW system is investigated using the characteristic equations of the power supply, wire and welding arc. The constant voltage power supply is modeled using a RL circuit, and the characteristic equation of wire is modified to include the effect of droplets attached at the electrode tip. A simple model for short-circuit, globular and spray transfer modes are predicted using the proposed model. The predicted results show reasonably good agreements with the experimental results with argon shielding. The proposed modeling technique appears to be utilized to determine the proper welding conditions and power supply design.
