A Study on the Correlation between Bead Geometry and Tensile Strength of Single Lap jointed Dissimilar Combinations through Regression Analysis

Abstract

In dissimilar overlap joints that are welded using gas metal arc welding, the shape of the weld bead changes due to changes in welding variables such as current, voltage, speed, and teaching position. The bead shape is a major factor that influences the evaluation of the tensile strength. Thus, it is crucial to control the shape of the bead and produce a bead with an optimal shape. In particular, in the case of a dissimilar combination with a thickness ratio of 4:1, it is difficult to weld all the joint surfaces of the upper plates. The presence of such a non-jointed area can change the tensile strength according to the bonded area. It is expected that a particular value of the critical jointed area satisfies the tensile strength constraints. In this study, various bead shapes were fabricated according to the welding parameters of dissimilar combinations with a thickness ratio of 4:1, and the corresponding tensile properties were evaluated. In addition, regression analysis was used to investigate the correlation between the bead shape and tensile strength.