A lumped-parameter model for sound generation in gas metal arc welding

It is found that the welding sound generated in Gas Metal Arc Welding (GMAW) can help human welders to improve welding quality; however, little work has been reported on the sound generation and prediction in GMAW processes. To investigate the sound generation in GMAW, this paper proposes a lumped-parameter model to predict the sound signals at the short-circuiting mode in GMAW, where the power source is modeled by a simple resistor–inductor electrical circuit and the metal droplet dynamics is modeled by a mass-spring model. The simulation results of the welding current, arc voltage, and sound signals are found to be in a reasonable agreement with the experimental measurements. Both simulation and experiment results show that the welding current increases from a base value in the arcing phase to a peak value in the short-circuiting phase first and then slumps to the base value; the voltage is close to zero in the short-circuiting phase corresponding to the current peaks and fluctuates in the arcing phase due to the uncertainties in the arc resistance; and an acoustic impulse is formed at each peak current and valley voltage in the short-circuiting phase, indicating that the sound generation is related to the energy release during the arc re-ignition process. The proposed lumped-parameter model can be used to investigate the effect of the input welding parameters on the welding sound.