Structural Engineering and Mechanics

Techno-Press (테크노프레스)
권호 표지
DOI QR코드

DOI QR Code

Fuzzy logic based estimation of effective lengths of columns in partially braced multi-storey frames

  • Menon, Devdas (Department of Civil Engineering, Indian Institute of Technology)
  • Published : 2001.03.25
⟨ Previous Next ⟩

Abstract

Columns in multi-storey frames are presently categorised as either braced or unbraced, usually by means of the stability index criterion, for estimating their effective length ratios by design aids such as 'alignment charts'. This procedure, however, ignores the transition in buckling behaviour between the braced condition and the unbraced one. Hence, this results in either an overestimation or an underestimation of effective length estimates of columns in frames that are in fact 'partially braced'. It is shown in this paper that the transitional behaviour is gradual, and can be approximately modelled by means of a 'fuzzy logic' based technique. The proposed technique is simple and intuitively agreeable. It fills the existing gap between the braced and unbraced conditions in present codal provisions.

Keywords

References

  1. ACI Committee 318 (1992), "Building code requirements for reinforced concrete and commentary (ACI 31889/318R89)", Sections 10.10 and 10.11, American Concrete Institute, Detroit.
  2. Albert, A. and Schnellenbach-Held, M. (1997), "The fuzzy-sets-theory and its applications in structural engineering", Darmstadt Concrete, Institut fur Massivbau, Technische Universitat Darmstadt, Germany, 12, 110.
  3. Aristizabal-Ochoa, J.D. (1994), "K-Factor for columns in any type of construction: nonparadoxical approach", Journal of Structural Engrg., ASCE, 120(4), 1272-1290. https://doi.org/10.1061/(ASCE)0733-9445(1994)120:4(1272)
  4. Aristizabal-Ochoa, J.D. (1995), "Story stability and minimum bracing in RC framed structures: A general approach", ACI Structural Journal, 92(6), 735-744.
  5. Cheong-Siat-Moy, F. (1986), "K-Factor Paradox", Journal of Structural Engrg., ASCE, 112(8), 1747-1759. https://doi.org/10.1061/(ASCE)0733-9445(1986)112:8(1747)
  6. Johnston, B.G. (ed.) (1976), "Guide to stability design criteria for metal structures", 3rd Ed., John Wiley & Sons, Inc., New York, 418-425.
  7. Klir, G.J. and Yuan, Bo. (1995), Fuzzy Sets and Fuzzy Logic, Prentice Hall Inc., Englewood Cliffs, N.J., 1-32.
  8. MacGregor, J.G. and Hage, S.E. (1977), "Stability analysis and design of concrete frames", Journal of the Structural Division, ASCE, 103(10), 1953-1970.
  9. Nambudiripad, K.B.M., Menon, D. and Kumar, N.V.P. (1998), "A fuzzy failure criterion in student evaluation", Proceedings, International Conference on Civil Engineering, CSCE, Halifax, Canada, I, 1-10.
  10. Newmark, N.M. (1949), "A simple approximate formula for effective fixity in columns", Journal of Aeronautical Sciences, 16(2), 116. https://doi.org/10.2514/8.11738
  11. Pillai, S.U. and Menon, D. (1998), Reinforced Concrete Design, Tata McGraw-Hill Publ. Co., New Delhi, 528-536.
  12. Rosenbleuth, E. (1967), "Slenderness effects in buildings", Journal of the Structural Division, ASCE, 91(1), 229-252.
  13. Smith, B.S. and Carter, C. (1969), "A method of analysis for infill frames", Proceedings, Inst of Civil Engineers, London, 44, 31-48.
  14. Stevens, L.K. (1967), "Elastic stability of practical multi-storey frames", Proceedings, Inst of Civil Engineers, London, 36, 99-117.
  15. Wood, R.H. (1974), "Effective lengths of columns in multi-storey buildings. Part I: Effective lengths of single columns and allowances for continuity", The Structural Engineer, 52(7), 235-244.
  16. Zadeh, L.A. (1965), "Fuzzy sets", Information and Control, 8, 338-353. https://doi.org/10.1016/S0019-9958(65)90241-X