Finite element analysis of resistance spot welding in aluminium

In the present work, an integrated simulation model has been developed for analysis of the resistance spot welding process in aluminium alloys via the finite element method. A coupled electrothermal analysis for art axisymmetric sheet - electrode geometry has been carried out that can predict the expected nugget diameter, penetration, and electrode face heating at any instant throughout the welding time. Several calculations have been carried out for different welding currents, welding times, and electrode forces and for different surface conditions of the aluminium sheets. Non-linear, temperature dependent, thermophysical material properties have been considered. An observation of interest is that in most instances the maximum nugget diameter is reached well within 0.02-0.04 s and further flow of welding current simply increases the electrode face heating. Also, the initial surface condition influences the growth of the fusion zone to a great extent. Various other conclusions have also been drawn.