An exact procedure for analysis including the nonlinear effects of axial forces in members is developed. It is extended to allow computation of the elastic critical load factor, lambda, to be applied to any load set to cause instability using an algorithm readily incorporated in standard computer programs. Lambda is used to determine the correct effective length for each member in the frame. The procedures are used to compare the correct amplification of bending moment with that specified in the beam - column capacity formula of design codes. It is found that bending moments arising out of loads not inducing sway are not amplified by the factor 1/(1 - omega/lambda) used in the design formula, where omega is the load factor. Bending moments associated with sway forces are amplified. For many practical cases the design formula is unduly conservative, and an alternative formula is proposed. (Author/TRRL)

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  • Corporate Authors:

    Monash University

    Wellington Road
    Clayton, Victoria  Australia  3800
  • Authors:
    • Grundy, P
  • Publication Date: 1980

Media Info

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Filing Info

  • Accession Number: 00329692
  • Record Type: Publication
  • Source Agency: ARRB
  • Report/Paper Numbers: Rpt. No. 4
  • Files: ITRD, TRIS, ATRI
  • Created Date: Oct 28 1981 12:00AM