Lateral Distortional Buckling of Monosymmetric Beams under Point Load

Abstract

Based on a new expression for the work done due to buckling, a computationally efficient method is presented for the lateral distortional buckling of monosymmetric beams. The method requires a knowledge of the stress distribution in the beam. For a simply supported monosymmetric beam subjected to a concentrated vertical load, a simplified stress distribution is assumed and the Rayleigh-Ritz method is used to analyze the lateral distortional buckling behavior. When distortion of the web is suppressed, the present approach agrees with the classical energy methods. However, for short beams and for concentrated loads, web distortion becomes important and the classical methods seriously overestimate the critical load. Other methods that have allowed for web distortion have been limited to end moments (or a cantilever), whereas this method can deal with any type of load including concentrated loads. The accuracy of the method is verified by results obtained from ABAQUS.