Torsional - flexural buckling strength of steel angles

Although structural steel angles have a wide variety of applications, they have not received attention comparable to that given to heavy shapes such as wide-flange sections. Because steel angles are singly symmetric or asymmetric, torsional-flexural buckling is an important mode of failure. The Canadian steel design practice for hot-rolled steel members (as given by CAN/CSA-S16.1-94) does not give a detailed procedure applicable to all sizes of steel angles. Some of the world codes applicable for steel angles specify torsional-flexural buckling check and plate buckling check to be considered simultaneously wherever applicable. The paper presents the results of an experimental investigation consisting of 34 hot-rolled steel angles under concentric compression (slenderness ratios between 50 and 150) failing in torsional?flexural buckling. The width to thickness ratios of test specimens ranged from 13 to 20. The results give a continuous spread of compressive strengths for practical ranges of slenderness parameters. The results show that torsional-flexural buckling and plate buckling need not be considered simultaneously even for unequal angles if they are designed according to CAN/CSA-S16.1-94. Key words: angle, buckling, codes and standards, compression, design strength, flexural buckling, local buckling, specifications, steel, torsional-flexural buckling.