GBT buckling analysis of thin-walled steel tubular members with regular polygonal cross-sections

摘要

This paper concerns the application of Generalised Beam Theory (GBT) to analyse the bucklingrnbehaviour of thin-walled steel members with single-cell regular polygonal cross-section, such as those employedrnto build transmission line structures, antennas and masts. First, the most relevant local and distortional crosssectionrnGBT deformation modes are obtained and examined. Then, the buckling (bifurcation) behaviour ofrnuniformly compressed members (columns) and members subjected to pure torsion is assessed with the help ofrnGBT-based semi-analytical formulae and beam finite elements. Attention is paid to both local and distortionalrn(flattening) buckling phenomena. For comparison and validation purposes, some results obtained are comparedrnwith values yielded by standard finite strip and shell finite element analyses.