Static strength of axially loaded EHS X-joints with braces welded to the narrow sides of the chord

•Static strength of axially loaded EHS X joint types 3 and 4 was investigated.•The numerical results agreed well with the experimental results.•A chord plastification limit state equation similar to CHS joints was derived.•The design strength can be determined following IIW and CIDECT recommendations.

Experimental tests and finite element (FE) studies have been carried out to investigate the static behaviour and strength of axially loaded X joints between elliptical hollow sections (EHSs) with braces welded to the narrow sides of the chord. The numerical results are in agreement with those obtained from the experiments. Based on the results of a numerical parametric study, an equation is derived to estimate the static strength. The equation is formulated in a similar way to that currently adopted for circular hollow section (CHS) joints for chord plastification. The design strength can be determined according to the procedures used in the IIW and CIDECT recommendations.