Torsional-flexural buckling of thin-wall column of open sections (using raleigh-ritz energy method)
Date
2025-08
Authors
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Publisher
Federal University of Technology, Owerri
Abstract
This study focuses on determining the torsional-flexural critical buckling load of thin-walled columns with open cross-sections. An equation for torsional-flexural buckling analysis was formulated using the principles of the Ritz energy method. The analysis considers thin-walled columns with open cross-sections of arbitrary slope. During buckling, deformation is assumed to involve a combination of twisting and bending about the two principal axes of the cross-section. The total potential energy functional is assumed as the sum of the strain energy functional U and the potential energy due to the external compressive load V. The governing equations were found to reduce to an algebraic eigenvalue–eigenvector problem. Buckling equations were obtained for singly symmetric, doubly symmetric, and generally asymmetric column sections. The resulting buckling modes correspond to torsional-flexural buckling. Generally, the critical buckling loads decrease as the column length increases. The findings are in excellent agreement with Jerath (2020)’s solution. For thin-walled columns with doubly symmetric open cross-sections and hinged (simply supported) boundary conditions at x=0 and x=l, the governing differential equations, buckling modes, and buckling loads are uncoupled. The torsional-flexural buckling equations for thin-walled columns with open cross-sections result in a set of three uncoupled equations involving three displacement variables: u, v, and θ, representing translational and rotational displacements, respectively. In the case of thin-walled columns with singly symmetric open cross-sections under axial compressive loading through the centroid, the buckling behavior is governed by a set of three homogeneous differential equations, two of which are coupled.
Description
This thesis is submitted for the award of the Master of Engineering (M.Eng) degree in Civil Engineering( Structural Engineering option)
Keywords
Single symmetric columns, double symmetric columns, asymmetric column, flexural torsional buckling mode, algebraic eigen vector problem, Department of Civil Engineering
Citation
Nwachukwu, I. M. (2025). Torsional-flexural buckling of thin-wall column of open sections (using raleigh-ritz energy method) [Unpublished Master's Thesis]. Federal University of Technology, Owerri, Nigeria