ABSTRACT
The continuity of the chord member is implicit in all truss-type welded Rectangular Hollow Section (RHS) connection design guidelines. Amendments to code have recently been submitted, which limit the end distances from the branch to an open chord end at which full connection strength can be developed. This paper investigates their applicability for RHS connections, by testing 12 RHS-to-RHS X-connections in the laboratory with the branch loaded in quasi-static axial compression. A modified yield line mechanism was found to control the behaviour of RHS X-connections near an open chord end. A proposed analytical model, by comparison with the experimental results, is shown to be an accurate predictor of the yield load. The associated closed-form solution for the critical end distance (to avoid a decreased connection strength) is thus justified for use with such RHS connections, in lieu of an EN amendment, providing chord face plastification is the governing failure mode.
