Heating of electrodes during spot resistance welding in FEM calculations

Due to the fact that many factors influence the electrode life, it is difficult to assess this impact experimentally. The study presents the analysis of the impact of individual factors on the heating of selected electrodes at specific operating parameters. The analysis was based on a SORPAS programme, intended for calculations related to resistance welding, in particular, to spot welding. In selected cases FEM calculations were verified experimentally through measurements of electrode temperature during welding cycles.The calculations were carried out for 1 + 1 mm and 2 + 2 mm plates made of steel DX52, for hard and soft parameters. The analysis involved various designs of an electrode tip (outer diameters of electrodes of 13, 16 and 20 mm as well as a bevel angle of 60° and 120° – in case of electrodes with flat working parts, and an end radius of 50 mm – in case of spherical electrodes). The tests also concerned the impact of the “height” of an electrode working area (i.e. the distance from the cooling duct of 10.5 mm and 3 mm) on temperature distribution in an electrode.