International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056 Volume: 04 Issue: 05 | May -2017 www.irjet.net p-ISSN: 2395-0072 © 2017, IRJET | Impact Factor value: 5.181 | ISO 9001:2008 Certified Journal | Page 681 Comparison of Structural Adhesive Joint with Spot and Seam Welded Joints Satish Kumar 1 , Dr. LC Singal 2 , Aishna Mahajan 3 1 Associate Professor, Department of Mechanical Engineering, CEC, Landran, Punjab, India 2 Professor, Department of Mechanical Engineering, CEC, Landran, Punjab, India 3 Associate Professor, Department of Mechanical Engineering, CEC, Landran, Punjab, India ----------------------------------------------------------------------***-------------------------------------------------------------------- Abstract - Structural adhesives provide a permanent flush type joint between two sheets without any obstructions. These join two thin sheets of equal, unequal thicknesses or join two dissimilar metallic sheets. Structural adhesives are replacing conventional joining methods such as welding, riveting and bolting because of number of inherent advantages. These are cost effective reducing the number of mechanical fasteners and surface preparation, free of any defects, aesthetic improvements over welding and mechanical fasteners, reduce stress concentrations, improve the strength of the materials being joined, spread the load more uniformly over the entire bonded area, reduce the chance for rust and corrosion, reduce the distortions or splitting because of absence of screw, bolt and rivets holes, cause no weakening of the material because of excessive heat in welding, increase fatigue and force resistance by increasing the stiffness of structures, reduces the overall weight of the assembly by not using heavy welding metals and mechanical fasteners, can be pre-applied to parts otherwise inaccessible to mechanical fastening, compensates for differences in the expansions and contractions of dissimilar materials, form resilient bonds and maintain its strength over a wide range of temperature of -51 0 C to 121 0 C.Thus use of structural adhesives is swelling day by day over a wide range of industrial and other applications because of high strength and inherent advantages. Experiments were conducted to compare the strengths of structural adhesive joints with spot and seam welded joints under the operating parameters namely materials used were 2mm and 3 mm cold rolled coil annealed (CRCA) and hot rolled coil annealed (HRCA) steels, Overlaps of 12.5, 25, 37.5 and 50 mm. However sample length and width in each case was 180 mm and 25 mm respectively. Total number of samples tested on the Universal Testing Machine was 24. SikaPower®- 4588 adhesive was used in the present investigation. The outcomes of the experimental finding are structural adhesive joints were the best in many cases and were encouraging in the remaining cases indicating replacement of conventional joints with the adhesive joints is a matter of time only. Keywords: Structural adhesive joint, spot and seam welded joints, overlap, bond strength, thin sheets. 1. INTRODUCTION Metallic thin sheets are widely used in all types of industries and can be joined by the different methods such as welding, riveting and bolting. But all these methods have inherent disadvantages of welding defects, distortions, stress concentrations, requiring more and skilled labor, more time consuming and more rejections of the finished assemblies. An alternative to these is the use of an adhesive joint. Adhesive bonding as a method of joining has a very long history and dates back to ancient times. Glues of animal origin, especially bone, hide and casein glues, were used quiet commonly. Common masonry mortars were essentially glues. This present study investigates the comparison of structural adhesive joints with spot and seam welding joining thin sheets. Structural adhesive-bonding provides several advantages over welding, riveting and bolting methods, such as reduction of stress concentrations, reduced weight penalty and easy manufacturing. Commercial structural adhesives range from strong and brittle to less strong and ductile ones. Various researchers have already advocated the use of adhesive joints instead of conventional joining of thin sheets [1-9].Thin sheet metal panels are joined with spot or seam welding depending on type of component & the nature of stiffening or strength required based on its intended function. But during the welding process, the spot welding marks become visible on outer surface & also distortions are observed which sometimes make the part unfit for use due to aesthetic requirements. To improve the quality of such joints, lot of rework is done by grinding/buffing on the outer surface to minimize unwanted visible defects. This reworking process on finished product is very time consuming & results in productivity loss due to high level of rejections. To take care of quality & productivity issues, the evolving technology is to paste the sheet metal parts with structural adhesive instead of spot or seam welding. In the present study, experiments have been performed for the comparison of performance analysis of adhesive joint over spot and seam welding. The various variable performance parameters are different types of material (Cold and hot rolled steels), different thicknesses (2mm and 3 mm),type of joining processes(adhesive, spot and seam welded