Lateral buckling of tee beams under moment gradient

This paper investigates the elastic lateral buckling of simply supported tee beams under moment gradient. Solutions are obtained via the energy approach, assuming a general Fourier sine series for the buckled shapes. It is found that buckling capacity of tee beams is greatly influenced by the inability of the web to resist compressive bending stresses. Although uniform moment is the most severe loading condition for inverted tee beams, this is not true in the case of tee beams. This study shows that a high moment gradient is generally a more critical form of loading for tee beams. Formula for the buckling moment modification factor for doubly symmetric I-beams found in design specifications and standard texts could be unsafe when applied to tee beams.