Research on the correlation between dynamic resistance and quality estimation of resistance spot welding

Abstract

In this paper, relevant twenty features were extracted from the dynamic resistance signal of the welding operation and subsequent mathematical models incorporating the qualifying features were developed to investigate the relationship among dynamic resistance, welding quality and welding parameters based on the stepwise regression method. The results of the analysis of variance indicated the peak point location t1, the initial resistance value r0, and the first slope k1 had little correlation with welding process parameters. The welding current is the most significant factor affecting the dynamic resistance signal, followed by welding time and electrode pressure. The welding current has significant effects on all the extracted features, while the electrode pressure only affects seven features. The model utilizing the features of rmean, re, rα, rβ and rmed was developed to predict the welding quality. rmean is the most significant factor in the model whose maximum relative error is less than 10%.