A COMPARISON OF THEORY AND PRACTICE IN PLATE STIFFENER BEHAVIOUR UNDER AXIAL LOADING

Bulb flats are asymmetric, tailor-made plate stiffeners manufactured in a range of sizes and grades. They have faced specific problems in the bridge building industry in the UK, and this paper documents research by British Steel Special Sections, in collaboration with Imperial College, London and the UK Highways Agency, to overcome these problems. The challenge to the researchers was to investigate shape limitations, contained in British Standard BS 5400 Part 3, which effectively excluded the use of bulb flats in bridges built in the UK, and favoured the use of flat bars. The shape functions in BS 5400 had been introduced to exclude the complex torsional buckling behaviour of bulb flats under axial compression. The study of shape limitations used FINASIC, a specialised finite element buckling program, and conducted several physical laboratory tests to verify its results. The aim was to produce new design rules that would allow the use of bulb flats in bridges designed by the Standard. The paper outlines the advantages of bulb flats, gives some examples of bridges where bulb flats have been used, reports on the research, and proposes a new method for determining the ultimate strength of a plate stiffened by bulb flats. It shows that BS 5400 imposes unnecessarily restrictive shape limitations. For the covering abstract see IRRD E104152.

  • Availability:
  • Corporate Authors:

    Thomas Telford Limited

    London,   United Kingdom 
  • Publication Date: 1999

Language

  • English

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00788359
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • ISBN: 0-7277-2841-5
  • Files: ITRD
  • Created Date: Mar 3 2000 12:00AM