Effect of defects on the strength of welds

Purpose – The purpose of this paper is an experimental investigation to determine the effects of defects on the strength of welds.

Design/methodology/approach – This investigation was carried out using butt-and fillet-welded specimens in tension. Several welding skills were incorporated into the investigation so as to come up with different types of defects. Half of the samples were welded flat and the other half, vertical.

Findings – Vertical welding resulted in a greater percentage of defects than flat welding. Most of the defects in the welds were a result of incomplete penetration, lack of fusion, slag inclusion, porosity and failure to weld to the given dimensions. The tests show that there is a linear relationship between the area of defects and the ultimate capacity of the joints.

Originality/value – Although the purpose of this research was to determine the effect of defects on the strengths of both butt and fillet welds, more attention was focused on fillet welds, as this investigation had not been carried out before. Fillet welds experience shear only, unlike butt welds which can either be in tension or shear, or, in rare cases, a combination of the two.