Flexural-Torsional Buckling of Columns with Oblique Eccentric Restraints (No. R841)

Abstract

This paper is concerned with the elastic flexural-torsional buckling of concentrically loaded columns with oblique eccentric restraints. Oblique flexural restraints may resist deflections as well as flexural rotations, while torsional restraints may resist twist rotations and warping. Flexural restraints may act at the shear centre or may be eccentric. Restraints may be concentrated at points along a column or distributed along portions of its length, and may be rigid or elastic. Oblique flexural restraints cause coupling between the principal axis deflections and rotations, while eccentric flexural restraints cause coupling between the principal axis deflections and rotations and the twist rotations and warping displacements. The general buckling mode involves simultaneous bending about both principal axes and torsion. This paper discusses the nature of oblique eccentric restraints, summarises their finite element analysis, presents examples of their effects on the elastic buckling of columns, and demonstrates the design of columns with oblique eccentric restraints.