Beams with Torsional and Flexural Loads

Wide-flange beams that are loaded in the plane of their minor axis and that have element width-thickness ratios that preclude plate buckling will fail either when lateral-torsional buckling occurs or when the material strength is reached. These possibilities are well documented, with design approaches available (8, 10). If a torque is additionally applied, such as would occur when the load is eccentric with respect to the minor axis, torsional stresses are created (5, 11). Present design practice involves adding vectorially the flexural and torsional stresses determined for each case separately. These are then compared with the maximum stresses determined for a beam loaded in flexure only. In doing this, the effects of interaction are neglected.