Journal of the Korea Concrete Institute (콘크리트학회논문집)

Korea Concrete Institute (한국콘크리트학회)
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A New Refined Truss Modeling for Shear-Critical RC Members (Part I) - lts derivation of Basic Concept -

전단이 지배하는 RC부재의 새로운 트러스 모델링 기법 연구 (전편) - 기본 개념 유도를 중심으로 -

  • Kim Woo (Dept. of Civil Engineering, Chonnam National University) ;
  • Jeong Jae-Pyong (Dept. of Civil Engineering, Chonnam National University) ;
  • Kim Dae-Joong (Dept. of Civil Engineering, Namdo Collage)
  • 김우 (전남대학교 토목공학과) ;
  • 정제평 (전남대학교 토목공학과) ;
  • 김대중 (전남도립남도대학)
  • Published : 2004.12.01
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Abstract

This paper describes a new refined truss modeling technique derived based on the well-known relationship of V=dM/dx=zdT/dx+Tdz/dx in a reinforced concrete beam subjected to combined shear and moment loads. The core of the model is that a new perspective on the shear behavior can be gained by considering the variation of the internal arm length along the span, so that the shear resistance mechanism can be expressed by the sum of two base components; arch action and beam action. The sharing ratio of these two actions is determined by accounting for the compatibility of deformation associated to the two actions. Modified Compression Field Theory and the tension-stiffening effect formula in CEB/FIP MC-90 are employed in calculating the deformations. Then the base equation of V=dM/dx has been numerically duplicated to form a new refined truss model.

이 논문은 휨과 전단이 동시에 작용하고 있는 철근콘크리트 보에서 전단은 휨모멘트의 변화율(V=dM/dx)이라는 기본 관계식에 근거한 새로운 트러스모델링기법을 제안하는 것이다. 이 새로운 모델의 핵심은 보의 경간에서 내부 모멘트 팔길이의 변화를 고려함으로써, 보의 전단 저항 메커니즘을 아치작용과 보작용이라는 두 기본 성분의 합으로 표현할 수 있게 한 것이다. 이두 작용에 의한 전단 저항 구성비는 상호 변형 적합조건을 적용하여 계산하였는데, 이 때 수정압축장이론과 CEB/FIP MC-90의 인장강화효과 공식을 이용하였다. 이렇게 함으로써 전단과 모멘트 관계식 V=dM/dx을 수치적으로 복제할 수 있는 새로운 트러스모델을 결정하였다.

Keywords

References

  1. ASCE-ACT Committee 426, 'The shear strength of reinforced concrete members,' Journal of Structural Division, ASCE, Vol.99, No.6, 1973, pp.1091-1187
  2. ASCE-ACT Committee 445, 'Recent approaches to shear design of structural concrete,' Journal of Structural Engineering, ASCE, Vol.l24, No.5, 1998, pp.1375-1417 https://doi.org/10.1061/(ASCE)0733-9445(1998)124:12(1375)
  3. ACI Committee 318, 'Building Code Requirement for Reinforced Concrete and Commentary,' ACI, Detroit, MI, l995
  4. Eurocode 2, 'Design of Concrete Structures-Part I, General Rules and Rules for Buildings,' British Standard Institution, London, 1992
  5. CEB/FIP, 'CEB-FIP Model Code for Concrete Structures,' Bulletin d' Information No.213/214, 1993
  6. Lampert, P. and Thurimann, B., 'Torsionsversuche an Stahlbetonkalken,' Bericht Nr. 6506-2, ETH, Zurich, German, 1968
  7. Schlaich, J., Schafer, I., and Jennewein, M, 'Towards a consistent design of structural concrete,' PCI Journal, Vo1.32, No.3, 1987, pp.74- 150 https://doi.org/10.15554/pcij.05011987.74.150
  8. Marti, P., 'Basic tools of reinforced concrete beam design,' ACI Journal, Vol.82, No.1, 1985, pp.46-56
  9. Nielsen, M P., 'limit Analysis and Concrete Plasticity,' Prentice-Hall, Englewood Cliffs, N. J, USA, 1984
  10. Vecchio, F. J and Collins, M P., 'The modified compression field theory for reinforced concrete elements subjected to shear,' ACI Journal, Vol.83, No.2, 1986, pp. 219-231
  11. Hsu, T. T. C., 'Unified Theory of Reinforced Concrete,' CRC Press, Boca Raton, Fla, 1991
  12. Ramirez, J. A. and Breen, J. A, 'Evaluation of a modified truss model approach for beams in shear,' ACI Structural Journal, Vol.88, No.5, 1991, pp. 562-571
  13. Niwa, J., 'Latice Model with Concrete Tension Members for Shear Resisting Mechanism of Concrete Beams,' CEB Bulletin d' Information No. 237, 1997, pp.l59-170
  14. Walraven. J. and Lehwalter. N, 'Size effect in short beams loaded in shear,' ACI Structural Journal, Vol.91, No.5, 1994, pp.585-593
  15. Leonhardt, F., 'Reducing the shear reinforcement in reinforced concrete beams and slabs,' Magazine of Concrete Research, Vol.l7, No.53, 1965, pp.l87-198 https://doi.org/10.1680/macr.1965.17.53.187
  16. Park, R and Paulay, T., 'Reinforced concrete structures,' Wiley, N. Y., 1975
  17. Barker, A. L. L. and Ahmad, S., 'A statically indeterminate truss model for reinforced concrete beams failing by shear,' Bulletin d'Inforrmation No.37, Comite Europeen du Beton, 1961, pp.208-219
  18. Kani, G. N J., 'The riddle of shear failure and its solution,' ACI Journal, Vo1.61, No.4, 1964, pp. 441-467