Inelastic behavior of single angle columns

Abstract The paper presents a theoretical investigation of the strength and behavior of single angle columns, with special emphasis on the inelastic response. Flexural and flexural-torsional buckling characteristics are examined, including residual stress and differential warping effects. A general solution is presented that is applicable to asymmetric shapes in general and angles in particular; to ease the incremental, iterative solution, the column length is found that corresponds to a certain load, rather than the other way around. It is shown that for unequal-legged angles, the flexural-torsional buckling load will always govern; for equal-legged angles the picture is more complex. Thus, for angles with low width-to-thickness ratios for the leg, the flexural and the flexural-torsional modes give essentially the same result. For high width-to-thickness ratios the elastic critical loads for the two modes of buckling are very close; in the inelastic range the flexural-torsional buckling load is the lowest. It is noted that further studies are needed, especially regarding the influence of the width-to-thickness ratios of the angle legs.