Beam and Column Buckling under Directed Loading

Abstract

Directed loading may have significant effects on the buckling resistances of beams and columns. Rotations of directed loads during buckling induce transverse components that may stabilize or destabilize the member. Previous studies of flexural‐torsional buckling are limited to specific situations. In this paper, a simple method is developed of modifying general finite element computer programs to account for the effects of directed loading on flexural‐torsional buckling. Computer results show that the buckling resistances of beams and cantilevers under downwards loading are increased when the load direction points are below the load application points and decreased when above. Members with top flange loads directed from above may have very low buckling resistances. Approximate equations are developed for simply supported beams and cantilevers. The accuracy of the computer predictions for cantilevered I‐beams is confirmed experimentally.