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This work compares three aluminium sheet joining processes to determine their capability, efficiency and cost for mass production applications in automotive structures and closures. The joining processes investigated are Resistance Spot Welding (RSW), Self-Pierce Riveting (SPR) and Spot Friction Joining (SFJ). Quantitative comparisons have been made on the basis of tensile strength (shear and peel), process time, equipment price and running cost. RSW is the most commonly employed joining method for steel sheet in the automotive industry. Its principle benefits are high speed and low cost operation, plus the ability to weld a wide range of joint configurations with the same gun. The main process limitations for aluminium are weld consistency and electrode-life, though recent work has shown that both of these can be largely overcome with regular electrode polishing [1, 2]. SPR is already in use for volume production of aluminium body structures.

Effective use of adhesive bonding in automotive vehicle bodies requires analytical methods for durability, so that potential fatigue problems and unnecessary overdesign may be eliminated before the physical prototype stage and release of product with unquantified safety factors avoided. This paper describes a fracture mechanics-based method for predicting the durability of adhesive joints, based on work previously carried out at Volvo [1]. The method requires relatively modest modifications to a typical vehicle body FE mesh. Adhesive bonds are represented by bar elements around the periphery of each bond. Grid point forces from shell elements adjacent to the adhesive bond are recovered and used to determine line forces and moments at the edge of the glued flange. These forces and moments are then transferred to an analytical sandwich model of the joint.