ABSTRACT
This chapter considers the beam-columns are initially straight and untwisted, the axial forces act concentrically through the centroid, and the transverse loads and moments act in the plane of section symmetry. Beam-columns are members with compressive axial forces and transverse loads or moments. Beam-columns which are bent in a plane of symmetry may fail by excessive bending in that plane, or may buckle out of the plane by deflecting laterally and twisting. A beam-column may have continuous or discrete restraints which restrict its buckled shape and increase its resistance to flexural-torsional buckling. When the axial force is zero, the beam-column has two different buckling moments. The higher one of these is positive, and occurs when the moment causes compression in the flange of the tee-section, while the lower one is negative, corresponding to a reversal in the sense of the moment which causes tension in the flange.
