Postyielding Behavior of Single Angles Bent around the Major Principal Axis

Abstract

An experimental study was conducted of the behavior of equal-leg and unequal-leg angles bent around the major principal axis. A finite-element model was developed for numerical simulation of the behavior and extensive computation. The results showed that the unequal-leg angle member generates out-of-plane deformation and torsion after the edge yields. The underlying mechanism is the neutral axis rotation of the unequal-leg angle section to maintain an equilibrium condition under the applied bending moment after the edge yields. The test results indicated that out-of-plane deformation and torsion after edge yielding affect the ultimate capacity of short-length unequal-leg angles subjected to major principal axis bending. The sensitivity of the behavior to imperfections also was studied. The test and analytical results were compared with the equations in the relevant specification and those proposed in the literature. The specification overestimates the effect of slenderness ratio. Overall, the specification is conservative.