Abstract: Dynamic liquid bridge profile in gas metal arc welding (GMAW) based on principle of minimizing energy is modeled. The energy of a small unit in liquid bridge tends to be minimizing under surface tension force, electromagnetic force, and gravity force, so a dynamic liquid bridge profile in GMAW is modeled. Dynamic behavior of liquid bridge is analyzed when dynamic model of GMAW welding circuit in short circuit period is associated. Deviations of model are discussed. The results show that the dynamic development tendency of liguid bridge profile is about the same in simulation and experiment. The factors that cause calculation deviations are arc blow, welding movement, welding pool action, shielded gas lugging.

Key words: Dynamic model, Gas metal arc welding(GMAW), Liquid bridge of short circuit transfer, Minimizing energy principle