The mechanical properties and geometrical configuration efficiency of multiple resistance spot welds

Abstract

The effects of multiple spot weld distribution on the mechanical properties of products manufactured by resistance spot welding of aluminium alloy AA5754 have been investigated. In addition to mechanical tests, finite element analysis was also carried out in order to develop a model for predicting the effects of different types of spot weld distribution patterns on the mechanical performance of resistance spot-welded structures. The results of experimental and simulation work for two-spot welds showed that the tensile strength and fatigue resistance of spot welded structures were better when both spot welds were in line with the principal stress direction. In the case of four-spot welds, a diamond-shaped configuration performed better than a square-shaped spot weld distribution. In this paper, the array of spot welds on a panel is described as a lattice in which the “unit cell” of each array is either a square shape or a diamond shape. This paper proposes that the most efficient configuration for multiple spot welds on a structure is a series of equally-spaced spot welds with a diamond shaped “unit cell” in which one of the diagonals of the “unit cell” is oriented parallel to the principal stress direction.

Keywords:

• Spot welding
• multiple spot weld distribution
• spot weld configuration
• weld failure mode
• fatigue failure