Simulation of dynamic behavior in a GMAW system

Abstract

The dynamic behavior of a GMAW system is simulated using a short circuiting transfer model incorporated with characteristic equations for the power supply, welding wire, and arc. The wire equation, which relates the variation of the wire extension to the wire feed and melting rates, is modified to include the effect of a molten drop attached at the wire tip. With this modification, the behavior of the GMAW system is described more precisely, and information about the initial bridge volume is provided to simulate the short circuit transfer. A short circuit model is proposed to predict the variation of short circuit parameters considering the effects of surface tension and electromagnetic force due to current. Variation of welding parameters are continuously simulated during short circuit as well as free-flight transfer modes, and the calculated results are in broad agreement with the experimental results that occur with argon shielding.