A series of tests has been carried out on I-section beams of B.S. 4360 Grade 55 type steel loaded into the inelastic range under a uniform bending moment. The flange width/thickness ratio was varied to evaluate the critical B/T ratio which would be suitable for use in load factor ( plastic ) design. In addition the mode of local buckling is described and it is shown how this may vary with the span. These modes are compared with the flange behaviour in stub-column tests showing similarities for sub-critical lengths. The future use of existing Universal Sections of high-strength steel for plastic design is shown to depend largely on the development of methods of analysis for determining realistic hinge rotation requirements in a structure. The factors involved are outlined and it is shown that the results of tests on full-size structures may help to solve this problem. In Appendix 1 a method of determining the extent of yielding in a partially yielded and buckled compression flange is presented. From a knowledge of the extent of yielding the average strain and hence the beam rotation capacity can be determined. An additional criterion concerning the required increased load capacity of the buckled flange is also described. Some beam deflection measurements obtained from tests on a full-size multi-storey steel frame are presented in Appendix 2 to indicate the rotation capacities required to arrive at the collapse condition.

  • Corporate Authors:

    British Iron and Steel Research Association

    24 Buckingham Gate
    London SW1,   England 
  • Authors:
    • Dibley, J E
  • Publication Date: 1970

Media Info

  • Features: Appendices; Figures; References; Tables;
  • Pagination: 32 p.
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00013832
  • Record Type: Publication
  • Report/Paper Numbers: EG/A/13/70
  • Files: TRIS
  • Created Date: Mar 23 1971 12:00AM