ABSTRACT
This chapter considers the out-of-plane strengths of beams which are susceptible to flexural-torsional buckling failure and discusses Australian and European code rules for designing against the flexural-torsional buckling of beams. It also considers the strengths and design of columns which fail in a flexural-torsional mode and of beam-columns. The maximum moment in a beam segment at elastic flexural-torsional buckling provides an upper bound to the beam strength. The moment failure states that must be considered for the limit states strength design of steel beams include yielding and local buckling of the cross-section, and plastic collapse or flexural-torsional buckling of the beam as a whole. A straight steel beam of intermediate slenderness fails before its elastic buckling load is reached, as a result of premature yielding caused by the in-plane actions and the residual stresses induced in it by the method of manufacture.
