Abstract
In experimenting with the lateral buckling of beams, there should be no lateral deflection, including torsion, up to the critical load in an ideal case. But in practice, owing to various kinds of imperfections, the beam begins to deflect laterally, including torsion, when loading commences. Thus the critical load is difficult to measure directly. In this paper, a modification of Southwell's method is proposed to determine the critical load from the test data on the load and the reactive torsional moment at the clamped end of the beam. In experiments with cantilever beams using a multicomponent loadcell developed by the authors, each critical load determined by the method agreed well with the theoretical value.
