Numerical study of CHS-SHS and CHS-RHS T-joints with chord web failure

Resumo

Hollow steel sections have properties that enable their use in large span structures and trusses, in which
the design of joints between chords and braces with hollow steel sections are composed of circular (CHS),
rectangular (RHS) or square (SHS) cross-sections. However, the current design prescriptions do not contemplate
the design of T-joints with containing slender cross-sections. In this work, CHS-SHS and CHS-RHS T-joints with
brace-to-chord ratios equal to one and composed of chords with slender sections were analysed through a
numerical analysis using a commercial software. A brace axial load of compression was applied, and the normal
tension distributions, the joint resistance and the load-displacement behaviour were examined. The numerical
results were compared with a design equation from a normative prescription. Chord web failure was observed in
all the joints analysed. Thus, the joints outside the current validity ranges of the normative prescriptions – that is,

with slender sections – presented the same predicted failure mode for joints with compact or semi-compact cross-
sections. The comparison between numerical and analytical joint resistances showed that current design equation

does not adequately predict the joint behaviour of joints with slender chords.