Buckling of Columns with Oblique End Restraints
In a previous project, the elastic behaviour of doubly symmetric columns with concentrated oblique translational and rotational elastic or rigid restraints was analysed, and used to study the effects of restraint type, angle, and stiffness on the flexural buckling of columns with end loads. However, any torsional buckling effects were eliminated from this project by its restriction to doubly symmetric section columns with concentric restraints.
This present project is concerned with the elastic flexural-torsional buckling of columns with oblique eccentric restraints under concentric loading. Oblique restraints cause coupling between the principal axis deflections and rotations, while eccentric restraints cause coupling between the principal axis deflections and rotations and the twist rotations and warping displacements. The buckling mode involves simultaneous bending about both principal axes and torsion.
Oblique restraints may resist deflections as well as rotations, while torsional restraints may resist twist rotations and warping. Restraints may be concentrated at point along a column, or distributed along portions of its length and may be rigid or elastic.
This project investigates the nature of oblique eccentric restraints, develops a finite element method of analysis, studies examples of their effects on the elastic buckling of columns, and proposes a method of designing columns with oblique eccentric restraints.
- Rasmussen, KJR and Trahair, NS, 'Exact and Approximate Solutions for the Flexural Buckling of Columns with Oblique Restraints', Thin-Walled Structures, 43(3), 2005, 411 – 26. See also School of Civil Engineering Research Report R834.
- Trahair, NS and Rasmussen, KJR, 'Finite Element Analysis of the Flexural Buckling of Columns with Oblique Restraints', Journal of Structural Engineering, ASCE, 131 (3), 2005, pp 481 – 7. See also School of Civil Engineering Research Report R835.
- Trahair, NS and Rasmussen, KJR, 'Flexural-Torsional Buckling of Columns with Oblique Eccentric Restraints', Journal of Structural Engineering, ASCE, 131 (11), 2005, pp 1731 – 7. (See also School of Civil Engineering Research Report R841.