Gap joints with tubular members— A yield line approach

The increased use of rectangular hollow section tubes in the fabrication of lattice girders has focussed attention on the joint problem. Previous elastic analyses, although useful in determining the onset of local yield, gave no real estimation of the strength of the joint. This paper presents a method of evaluating the static collapse load of a gap joint, based on the widely used yield line approach for the analyses of reinforced concrete slabs. The theory enables a quantitative estimate of the relative significance of the joint parameters to be made.