DESIGN AND DEVELOPMENT OF FRACTURE- RESISTANT WELD BONDS OF AL-ALLOYS

Abstract

The increasing restrictions in terms of performance, safety and energy consumption imposed in transport vehicles construction promotes the use of new materials and new processes searching weight reduction . Lighter materials along with better joining methods, like weld-bonding can contribute to obtain some weight reduction. Present work studies the shear strength and distribution of stresses in weld-bonds and spot-welded joint through finite element analysis and compares the results with the results obtained through experimental procedures. The single lap joints were obtained with thin plates of A16082-T651 alloy with high strength two components epoxy (araldite) and two weld spots. The strength of weld-bonded joints is found significantly higher than equivalent spot welded joints. In the present work, efforts were made to perform FE analysis of spot-welded and weld-bonded joint of A16082 T6 alloy. A numerical study of the effect of variation in pitch distance with constant nugget diameter and the effect of increase in nugget —diameter with the variation in pitch-distance on the joint-strength of both spot-welded and weld-bonded joint is carried out using three-dimensional finite-element method. The result shows the variation in nugget diameter with pitch distance affect the strength of spot-welded joint, with little effect on weld-bonded joint. Variation of pitch distance plays major role in evaluating the strength of spot welded joint. The strengths of these joints based on elastic-plastic finite-element method are co-incident with the experimental result.