Abstract:
The aim of this research was to devise an innovative technique to
obtain an objective assessment of the quality performance of tubular cored
wires by sensing and measuring the signals available during welding. The
work comprised:
Identification of the parameters to assess.
A study of the different monitoring techniques.
Design of specific quality evaluation methods.
The production of a system which allowed a quality index of welding
performance to be obtained.
Initially, the arc voltage, arc current, wire feed rate, arc light and arc
sound signals were identified as possible sources of useful information. After
a useful technique was accepted, the non-useful techniques were abandoned
and a quality measuring instrument was built. The work involved development
of statistical analysis techniques, Fast Fourier Transforms and mathematical
modelling. A new approach to process modelling was devised which
provided an objective and very flexible method of assessing, comparing and
developing welding consumables.
The final system was evaluated against conventional subjective
assessment techniques and very good correlation was obtained.
