Mathematical modelling of GMAW process using sound pressure measurements

A burning of the electric arc produces strong side effects such as UV light, heat, vibrations of the burning electrode, acoustic emission, and audible sound. In addition to variable welding voltage and current, a distinctive characteristic of arc welding processes is the pressures of audible sound phenomena which reflect the variable conditions in the arc to the highest extent. Measurements and analysis of audible sound generated by the GMAW are presented in this paper. Results indicate that more information about the welding process is embedded in the sound signal as in the welding current signal or/and in the welding voltage signal. An additional advantage of sound implementation into the control algorithms is simplicity of its detection. The mathematical model for the calculation of sound from the welding current is presented. The model can be implemented for the calculation of welding process parameters in real–time applications.