Buckling behaviour of uniformly and non-uniformly pretwisted beams

The buckling behaviour of continuously, discontinuously and oppositely pretwisted beams under a variety of combinations of twist angle and cross-section has been analysed. Both uniformly and non-uniformly twisted beams are considered. The twisted rod is modelled as a beam with varying bending strength depending on the twist. A Cartesian global coordinate system is used with a rotating local coordinate system in deriving the governing system of differential equations. These are then solved using the Galerkin finite element formulation with the Hermite polynomials as interpolating functions. The various combinations of parameters are compared and the characteristic behaviour of each family indicated. The choice of combinations in order to maximize the buckling load have been considered. © 1995.