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.
Original language | English |
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Article number | 107194 |
Number of pages | 13 |
Journal | Thin-Walled Structures |
Volume | 158 |
Early online date | 15 Oct 2020 |
DOIs | |
Publication status | Published - Jan 2021 |
Keywords
- Cold-formed steel
- web crippling
- experiments
- FE model
- Slenderness
- Lipped sigma sections
- Design
- Interior one flange loading
- Web crippling
- Experiments
ASJC Scopus subject areas
- Mechanical Engineering
- Building and Construction
- Civil and Structural Engineering