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Plasticity Model for Directionality of Concrete Crack Damages

콘크리트 균열 손상의 방향성을 고려한 다중파괴기준 소성 모델

  • Kim, Jae-Yo (High-Rise Team, Samsung Engineering & Construction) ;
  • Park, Hong-Gun (Dept. of Architecture, Seoul National University)
  • 김재요 (삼성물산(주) 건설부문 초고층팀) ;
  • 박홍근 (서울대학교 건축학과)
  • Published : 2007.10.31

Abstract

The inherent characteristic of concrete tensile cracks, directional nonlocal crack damage, causes so-called rotating tensile crack damage and softening of compressive strength. In the present study, a plasticity model was developed to describe the behavior of reinforced concrete planar members In tension-compression. To describe the effect of directional nonlocal crack damage, the concept of microplane model was combined with the plasticity model. Unlike existing models, in the proposed model, softening of compressive strength as well as the tensile crack damage were defined by the directional nonlocal crack damage. Once a tensile cracking occurs, the microplanes of concrete are affected by the nonlocal crack damage. In the microplanes, microscopic tension and compression failure surfaces are calculated. By integrating the microscopic failure surfaces, the macroscopic failure surface is calculated. The proposed model was implemented to finite element analysis, and it was verified by comparisons with the results of existing shear panel tests.

콘크리트의 인장균열에 따른 방향적 비국소 손상이라는 특징은 인장-압축을 받는 철근콘크리트 전단 부재에서 회전인장균열 특성 및 압축강도 감소 현상을 일으킨다. 본 연구에서는 인장과 압축거동에 대하여 다른 손상 모델을 사용하는 기존의 방법과는 달리, 동일한 인장균열 손상 모델을 사용하여, 인장균열거동과 압축연화거동을 나타낸다. 이러한 비국소 균열 손상의 영향을 나타낼 수 있는 소성모델을 개발하기 위하여 미소면 모델의 개념을 도입한다. 기존의 소성모델과 달리, 비국소 균열 손상을 나타내기 위하여 인장과 압축의 소성파괴면은 각 미소면에서 정의하며, 각 미소파괴면의 조합에 의하여 대표파괴면을 정의한다. 이때, 방향적 비국소 균열 손상을 나타내는 소성인장변형률의 영향에 의하여 각 미소면의 인장과 압축 소성변형률의 크기가 결정된다. 본 연구에서 개발된 소성모델은 유한요소해석에 적용되며, 다양한 전단패널의 기존 실험 결과들과 비교하여 제안된 재료 모델의 유효성을 검증한다.

Keywords

References

  1. Vecchio, F. J. and Collins, M. P., 'The Modified Compression-Field Theory for Reinforced Concrete Elements Subjected to Shear', ACI Struct. J., ACI, Vol.83, No.2, 1986, pp.219-231
  2. Feenstra, P. H. and de Borst, R., 'A Composite Plasticity Model for Concrete', Int. J. Solids and Struct., Pergamon, 33(5), 1996, pp.707-730 https://doi.org/10.1016/0020-7683(95)00060-N
  3. Belarbi, A. and Hsu, Thomas T. C., 'Constitutive Laws of Softened Concrete in Biaxial Tension-Compression', ACI Struct. J., ACI, Vol. 92, No.5, 1995, pp.562-573
  4. Okamura, H. and Maekawa, K., Nonlinear Analysis and Constitutive Models of Reinforced Concrete, Gihobo, Tokyo, Japan, 1991
  5. de Borst, R. and Nauta, P., 'Non-Orthogonal Cracks in a Smeared Finite Element Model', Engrg. Computations, 2, 1985, pp.35-46 https://doi.org/10.1108/eb023599
  6. Bazant, Z. P. and Prat, P. C., 'Microplane Model for Brittle-Plastic Material', J. Eng. Mech., ASCE, Vol.114, No.10, 1988, pp.1672-1688 https://doi.org/10.1061/(ASCE)0733-9399(1988)114:10(1672)
  7. Bazant, Z. P., Xiang, Y., and Prat, P. C., 'Microplane Model for Concrete', J. Eng. Mech., ASCE, Vol.122 No.3, 1996, pp.245-254 https://doi.org/10.1061/(ASCE)0733-9399(1996)122:3(245)
  8. Park, H. and Kim, H., 'Microplane Model for Reinforced-Concrete Planar Members in Tension-Compression', J. Struct. Engrg., ASCE, Vol.129, No.3, 2003, pp.337-345 https://doi.org/10.1061/(ASCE)0733-9445(2003)129:3(337)
  9. Park, H. and Klingner, R. E., 'Nonlinear Analysis of RC Members Using Plasticity with Multiple Failure Criteria', J. Struct. Engrg., ASCE, Vol.123 No.5, 1997, pp.643-651 https://doi.org/10.1061/(ASCE)0733-9445(1997)123:5(643)
  10. Chen, W. F., Plasticity in Reinforced Concrete, McGraw-Hill, New York, 1982, pp.204-217
  11. Feenstra, P. H. and de Borst, R., 'Aspects of Robust Computational Modeling for Plain and Reinforced Concrete', Heron, 4, 1993, pp.5-26
  12. Kim, J., Enhanced Multiple-Criteria Plasticity Model for Concrete Considering Crack and Stress Directionality, PhD Thesis, Seoul National University, Seoul, Korea, 2004
  13. Karsan, I. D. and Jirsa, J. O., 'Behavior of Concrete under Compressive Loadings', J. Struct. Engrg., ASCE, Vol.95, No.12, 1969, pp.2543-2563
  14. Park, H. and Kim. J., 'Hybrid Plasticity Model for Reinforced Concrete in Cyclic Shear', Engrg. Struct., Vol.27, No.1, 2005, pp.35-48 https://doi.org/10.1016/j.engstruct.2004.08.013
  15. Smith, S. S., Willam, K. J.,Gerstle, K. K., and Sture, S., 'Concrete over the Top, or: Is There Life after Peak?', ACI Mat. J., ACI, Vol.86, No.5, 1989, pp.491-497
  16. Vecchio, F. J., The Response of Reinforced Concrete to In-Plane Shear and Normal Stresses, PhD Thesis, Univ. of Toronto, Ont., Canada, 1981
  17. Ohmori, N., Takahashi, T., Inoue, H., Kurihara, K., and Watanabe, S., 'Experimental Studies on Nonlinear Behaviors of Reinforced Concrete Panels Subjected to Cyclic In-Plane Shear', Tran. AIJ, 403, 1989, pp.105-117
  18. Belarbi, A., Stress-Strain Relationships of Reinforced Concrete in Biaxial Tension-Compression, PhD Thesis, University of Houston, 1991
  19. Vecchio, F. J., Collins, M. P., and Aspiotis, J., 'High-Strength Concrete Elements Subjected to Shear', ACI Struct. J., ACI, Vol.91, No.4, 1994, pp.423-433
  20. ACI 224.2R-92, 'Cracking of Concrete Members in Direct Tension', ACI Manual of Concrete Practice, ACI, 2004, pp.3-4