Slenderness-based design for sigma sections subjected to interior one flange loading

Research output: Contribution to journalArticlepeer-review

Authors

Colleges, School and Institutes

External organisations

  • University of Wolverhampton

Abstract

Due to their thin-walled nature and complex geometry, cold-formed steel purlins are prone to a variety of instabilities. Sigma purlins are a family of cold-formed steel members with folding-lines along their webs. The non-straight geometry of their web is beneficial in terms of reducing the susceptibility of the web to local buckling, however, it increases their susceptibility to web crippling when the purlins are subjected to concentrated transverse loads and hence it may reduce their overall moment resistance. This paper reports a series of experiments on sigma purlins under the interior-one-flange (IOF) loading condition. Two different section geometries and three different bearing plate widths were examined. To investigate further the effect of web geometry on the IOF web crippling strength of sigma sections, an FE model was developed and validated against the reported test results. Following successful replication of the experimental observations, a comprehensive parametric study was performed, and several sigma sections covering a wide range of cross-sectional geometries and slenderness were numerically modelled. Finally, a slenderness-based (or direct strength) design approach previously developed for the web crippling design of channel and hat sections is extended to sigma sections.

Details

Original languageEnglish
Article number107194
Number of pages13
JournalThin-Walled Structures
Volume158
Early online date15 Oct 2020
Publication statusPublished - Jan 2021

Keywords

  • Cold-formed steel, web crippling, experiments, FE model, Slenderness, Lipped sigma sections, Design, Interior one flange loading, Web crippling, Experiments