International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395-0056
Volume: 11 Issue: 02 | February 2024
p-ISSN: 2395-0072
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Optimisation of weld size in single-sided groove butt joint Sandeep Chowdhry1 1 Engineering Consultancy & Training
Chandigarh, India ---------------------------------------------------------------------***---------------------------------------------------------------------
Abstract - The welding parameters influence the static
effect of factor of safety on the weld size; 4) To use FEA model to find the effect of electrode tensile strength on the weld size 5) To develop a mathematical model to predict the required weld size. This study aims to contribute to an understanding of using an appropriate optimisation method to enhance the weld size. In addition, it will help in understanding the effect of applied load, safety factor and electrode tensile strength on the single-sided butt joint weld size.
strength of the butt weld joint used in the mechanical structures. It is essential to make correct-size welds, as an oversized weld is very costly and may not have good strength. It wastes welding consumables and may cause other fabrication problems, including excessive distortion. This study aims to use an appropriate optimisation method and finite element analysis model to develop a mathematical model to predict the required weld size. The results show that half-fraction factorial design is an appropriate optimisation method. The increase in applied load and safety factor leads to an increase in the required weld size. The lower tensile strength electrode leads to a bigger weld size. The developed mathematical model predicted the size of weld needed for a single-sided groove butt joint for the range of the used parameters.
2 STATIC JOINT DESIGN To satisfy the welding criteria [1], alloy steel is selected as the base material of the plates to be butt welded. The base material has a minimum yield strength of 620 MPa (< 690 MPa) and a base material plate thickness of 6 mm (>3mm). Electrode filler material strength mismatch m in welds is the ratio of filler material yield strength to the base material's yield strength. Based on this ratio, if m < 1, the case is called under-matching [2]. The study [5] recommended a mismatch ratio of m <= 0.7 for the testing of the butt weld joints. Therefore, in this study, electrodes E60 and E70 are selected as the electrode filler material yield strengths are 458.5 MPa and 479.9 MPa, respectively. As a result, the mismatch ratio is 0.7 and 0.77, respectively.
Key Words: butt weld, optimisation, finite element analysis, weld size, single-sided groove butt joint
1. INTRODUCTION A butt joint is the most accessible welding joint to perform (next to the fillet weld). It is high strength with complete fusion and somewhat less susceptible to contamination. It is easy to inspect for distortion, easy to machine after welding and applicable to a variety of metals. It is excellent for continuous linear or circumferential welds. Filler material strength, base material strength, and weld geometries, such as weld size, are essential factors in evaluating static strength [1]. The study [3] developed an appropriate method for predicting the ultimate tensile strength of partially penetrated groove welds and proposed design equations. The study [4] developed expressions for predicting the ultimate load and deformation capacities in the fillet welds. The study [5] shows that a finite element analysis (FEA) model could be developed whose estimations for load carrying capacity of butt-welded joints agree with the experiment results. The above studies indicate that the requirement of the weld size in single-sided groove butt weld may vary with different combinations of applied load, the factor of safety and electrode material strength.
2.1 Specimen geometry A specimen of alloy steel material with dimensions of 400 mm x 37 mm x 6 mm, as shown in Fig. 1, was used for FEA. The FEA model was built as an assembly using mate constraints on two plates of size 200 mm x 37 mm x 6 mm. An alloy steel has a yield strength of 620 MPa and an ultimate tensile strength of 723.8 MPa.
Therefore, this study's main aim is 1) To select an appropriate optimisation method to refine the weld size; 2) To use FEA model to find the effect of applied tensile load on the weld size; 3) To use FEA model to find the
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