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

J Achebo,S Nweze

doi:10.24018/ejers.2021.6.2.2226

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.

Highlights

In different parts of Nigeria, there have been the incessant collapse of metal materials, some of which are reported and so many are not reported
To improve ultimate tensile strength (UTS), CVN, Bead height (BH) and Bead width (BW), it is imperative that the optimum input parameters should be achieved, this can be through experimental means either by trial and error or modelling
There are some authors that have worked on the optimization, [3] worked on air conditioner selection problem with Complex Proportional Assessment (COPRAS) and Addition Ratio Assessment (ARAS) methods. [4] evaluated some contractors using COPRAS, [5] to reduced greenhouse gas emissions in grassland ecosystems off the central Lithuania using ARAS method

Summary

INTRODUCTION

In different parts of Nigeria, there have been the incessant collapse of metal materials, some of which are reported and so many are not reported. Some of these failures are castatrophic and human lives are lost, or the injury sustained could lead to permanent disability [1] Most of these failures results from poor weldment leading to compromised UTS, CVN, BH and BW which is very critical in achieving good weld. To improve UTS, CVN, BH and BW, it is imperative that the optimum input parameters should be achieved, this can be through experimental means either by trial and error or modelling. This study uses the application of COPRAS – ARAS method to select the optimum process parameters, since it has been confirmed by researchers that selecting the appropriate input process parameters could lead to improving the welded joint quality. It has been researched that what influences weldments quality is the welding input parameters

Materials

Methods

RESULTS AND DISCUSSION

Discussion of Results

CONCLUSION