Numerical investigation of cold-formed steel top-hat purlins

Asraf Uzzaman, Andrzej Wrzesien, Robert Hamilton, James B.P. Lim, David Nash

Research output: Contribution to conferencePaper

2 Citations (Scopus)


This paper considers the use of cold-formed steel top-hat sections for purlins as an alternative to conventional zed-sections. The use of such top-hat sections may be viable for use in cold-formed steel portal framing systems, where both the frame spacing and purlin span may be smaller than in conventional hot-rolled steel portal frames. Furthermore, such sections are torsionally stiffer than zed- sections, and so have a greater resistance to lateral-torsional buckling. They also do not require the installation of anti-sag rods. The paper describes non-linear elasto plastic finite element analyses conducted on top-hat sections. The results of twenty-seven tests on four different top-hat sections are presented. Good agreement between experimental and finite element results is shown. The finite element model is then used for a parametric study to investigate the effect of different thicknesses and steel grades. Design recommendations are provided in the form of charts that can be used to assist designers when deciding which geometry of top-hat section to consider for further development. The use of the finite element method in this way exploits modern computational techniques for an otherwise difficult structural design problem and reduces the need for an expensive and time consuming full laboratory study, whilst maintaining realistic and safe coverage of the important structural design issues.
Original languageEnglish
Number of pages15
Publication statusPublished - 5 Nov 2014
Event22nd Special conference on cold-formed steel structures - St. Louis, United States
Duration: 5 Nov 20146 Nov 2014


Conference22nd Special conference on cold-formed steel structures
Abbreviated titleCCFSS
CountryUnited States
CitySt. Louis



  • Purlins
  • Top-hat sections
  • Finite element modeling
  • Cold-formed steel
  • Structural design and analysis

Cite this

Uzzaman, A., Wrzesien, A., Hamilton, R., Lim, J. B. P., & Nash, D. (2014). Numerical investigation of cold-formed steel top-hat purlins. Paper presented at 22nd Special conference on cold-formed steel structures, St. Louis, United States.