Quality Evaluation of Resistance Spot Welding Based on Dynamic Reactance Signal and Radar Diagram Method

In order to develop a real-time and effective method for nondestructive assessment of resistance spot welding quality, a measurement system is designed based on which the dynamic reactance signals generated by mutual inductance phenomena during resistance spot welding are captured. An innovative and dynamic signal visualization method is proposed; the captured reactance signal characteristic data is first mapped into radar charts format, and then the weld quality is reflected by some geometric feature quantities of the radar charts. A welding quality classifier is established using a decision tree approach, and the test results of the classifier demonstrate that it is feasible and productive to visualize and evaluate the welding quality by visualizing the characteristic parameters of reactance curves related to the welding process in a radar chart format and that these features are closely related to the welding quality.