Comparative Enhancement of Mild Steel Weld Mechanical Properties for Better Performance Using COPRAS–ARAS Method

Abstract

Some machine part failures have often occurred in areas of components where the strength was lowest, especially at its weld region. Presence of voids in weldments or weld joints greatly reduces the quality of the weldment. To prevent these defects, a proper optimum selection of process parameters is highly encouraged to achieve an acceptable weld mechanical property. The Complex Proportional Assessment (COPRAS) method was applied to determine the relative significance of each alternative and the quantitative utility for each alternative. The Addition Ratio Assessment (ARAS) method was applied to optimize these parameters by utilizing the weights generated using COPRAS method. In this study, the COPRAS-ARAS method which is a multi-criteria decision making tools was applied to determine the optimum process parameters to improve the mechanical properties of the weldment. From applying these methods, it was found that weldments 7, possess the optimum input process parameters. The corresponding mechanical properties of ultimate tensile strength (UTS) of 395MPa, absorbed impact strength (CVN) of 250J, Bead height (BH) of 1.98mm and Bead width (BW) of 4.82mm was found to possess the best mechanical properties.