BUCKLING OF COLUMNS UNDER AXIAL LOADS AND TORSIONS

Abstract

The buckling of thin-walled open section columns due to axial forces and conservative torsions are presented in this paper. Greenhill has studied first on the buckling of a column with a solid section under the same loads. Ziegler has pointed out that the buckling under consideration should be classified into two categories, namely the conservative and non-conservative bucklings. He also divided the conservative torsions into quasi-tangential, semitangential and pseudotangential torsions, and computed characteristic values of buckling for each cases.
In order to obtain stability equations of the columns with the thin-walled open sections, the total potential energy is formulated by using the concept of the initial stresses.
The differential equations governing buckling of the columns under the axial forces and the conservative torsions are derived from the total potential energy.
The obtained boundary conditions of bending moments coincide with the semitangential moments defined by Ziegler for the columns having two axes of symmetry.
The buckling of a channel section column is studied and the effects of warping and torsional deformations on the buckling are investigated.