Effect of Load Height on Buckling Resistance of Steel Beams

This paper presents a detailed investigation of effect of load height on buckling resistance of steel beams. Shapes that are intended to be used primarily as a beam are generally proportioned so that moment of inertia about the principal axis is considerably larger than that about minor axis. Hence monosymmetric sections are preferable. The lateral stability of beam subjected to transverse loading is very complicated in monosymmetric sections. The distance of transverse load from shear centre axis may significantly affect the buckling resistance of a simply supported beam. When transverse concentrated load W acts at (Yq-Yo) below the shear centre and moves with the beam it acts as an additional torque W(Yq-Yo) about shear centre which opposes twist and increases resistance to buckling. Conversely, when load above shear centre, additional torque increases the twist rotation and reduces buckling resistance of beam. To verify the effect of load height on buckling resistance, a simply supported beam subjected to concentrated and uniformly distributed load is considered. The effect of load height on buckling resistance has been plotted.