Plastic Buckling of T-Beams under Pure Bending

Abstract

This paper presents the results of a combined experimental and analytical study of the response and buckling of elastic-plastic T-beams under pure bending. Special attention in the investigation was paid to the role that the deformation of the cross section played in the response, buckling, and collapse of the beams. Buckling of the specimens occurred at lower curvatures when bending was so that the tip of the web was in compression. Although some results are shown for bending in the opposite direction, the investigation focused on the earlier case. Collapse occurred due to a limit moment instability that was accompanied by the formation of a local buckle. The development of the local buckle involved interaction between an axial ripple pattern in the deflection of the web and roll of the cross section along the beam. The analytical predictions agreed well with experimental results of the moment-curvature response and of the onset of the ripple in the web.