Effects of Current Waveforms on TIG Welding Arc Sound

Investigation on Welding Arc Sound (Report 3)

Abstract

Investigations have been made of the effects of the rectangle, sawtooth, triangle and sine current waveforms on the welding arc sound of TIG arc, that is a stationary arc on the water cooled copper plate, by means of a transistor control type power source.
The experimental results have indicated that the welding arc sound depends on the current wavetorm, repetition frequency fp and amplitude τ_p. The welding arc sound is composed of a fundamental tone which has a frequency spectrum of f_p and its harmonics. An excellent frequency spectrum fig agrees with fp in the triangle and sine wave current, but fox changes to higher harmonic in the rectangle and sawtooth wave current.
The effective sound pressure P_e is shown as a function of f_p and τ_p(P_ef_p^m⋅τ_pⁿ), and the useful equations which are possible to estimate the noise level have been obtained.