Interactive local buckling and limiting slenderness of T-strut stem

This paper presents in the first place an analytical solution by energy approach to the interactive buckling of plate elements of T-sections subject to axial compression. The critical stress obtained is then compared to that of the strut buckling torsionally with respect to its shear center and the identity of these two stresses is revealed. Further analysis shows that stem buckling stress is always larger than the flexural–torsional buckling stress in the case when the strut is not restrained by any other member. A limiting depth–thickness ratio of the stem is derived on the basis of a plate element with one longitudinal edge built-in and the other free. Finally, the relevant provision in the Chinese code for design of steel structures is introduced.