Abstract
This paper compares different techniques for determining the strength of fillet welded lap joints under eccentric shear loading and assesses the benefit of having a torsionally closed, continuous fillet weld seam in preference to a torsionally open joint. The validity of generally using analysis based on simple torsion theory, as widely proposed in numerous design texts, is questioned and the alternative of using tubular, thin-walled section and thin rectangular member torsion theory is investigated. The accuracy of the various torsional analytical techniques as applied to analysing torsionally open and closed section weld seams are compared with those given by a finite element analysis.