A Quality Improvement Approach for Resistance Spot Welding using Multi-objective Taguchi Method and Response Surface Methodology

Abstract

This research deals with an approach for optimizing the weld zone developed by the resistance spot welding (RSW). This approach considers simultaneously the multiple quality characteristic (weld nugget and heat affected zone) using Multi-objective Taguchi Method (MTM). The experimental study was conducted under varying welding currents, weld and hold times for joining two sheets of 1.0 mm low carbon steel. The setting of welding parameters was determined using Taguchi experimental design method and L9 orthogonal array was chosen. The optimum welding parameter for multi-objectives was obtained using multi signal to noise ratio (MSNR) and the significant level of the welding parameters was further analyzed using analysis of variance (ANOVA). Furthermore, the first order model for predicting the weld zone development was developed by using Response Surface Methodology (RSM). Confirmation experiment was conducted at an optimal condition for observing accuracy of the developed response surface model. Based on the confirmation test results, it is found out that the developed model can be effectively used to predict the size of weld zone which can improve the welding quality and performance in RSW.