Buckling of Struts

Abstract

Euler’s theory predicts the axial compressive force required to initiate bucking in a long thin strut. Ideally, a perfectly straight strut, when subjected to a purely compressive load, would compress and not buckle. Buckling is therefore the result of imperfections that prevent the load from being applied perfectly axially; e.g. from eccentric loading and lack of initial straightness. The combined effects of these imperfections on overall buckling behaviour is predictable when long struts are to operate under elastic conditions. We need only derive an instability criterion from the lateral deflection that occurs. This approach is attributed to Leonhard Euler (1707–83). It can be applied to long struts with the following end fixings.