The influence of electrode tip radius on dynamic resistance in spot welding.

Electrode wear has a major impact on the quality of the spot welding joint. It is important to evaluate the electrode tip condition based on a simple method. In this paper, the dynamic resistance is analyzed, and the relationship between the dynamic resistance and the radius of electrode tip is investigated. It is difficult to obtain the relationship between the electrode tip radius and real-time dynamic resistance. The dynamic resistance is represented by the sum of the squares of the real-time resistances in every half cycle. It is virtually impossible to research the electrode tip radius based on only one dynamic resistance of spot welding joint. The average value of dozens of dynamic resistances should be analyzed, and the means of 20 dynamic resistances are analyzed in this study. The average value of dynamic resistances from the first to seventh cycle during the nugget-growth stage has a strong corresponding relation to the electrode tip radius, which can be used to evaluate the electrode wear. [ABSTRACT FROM AUTHOR]