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반복하중을 받는 철근콘크리트 보의 에너지소산계수 변화 특성 고찰

Study on the Variation of Energy Dissipation Factor of Reinforced Concrete Beam under Cyclic Loading

  • 유석형 (경상국립대학교 건축공학부) ;
  • 강대영 (경상국립대학교 건축공학부)
  • 투고 : 2023.10.25
  • 심사 : 2023.11.24
  • 발행 : 2023.12.31

초록

반복하중을 받는 철근콘크리트 부재는 이력거동이 진행됨에 따라 강성과 강도의 저하 그리고 핀칭현상 등으로 인하여 에너지소산 능력이 감소된다. 그러나 지침서 「철근콘크리트 건축구조물의 성능기반 내진설계를 위한 비선형해석모델, 2021」에서는 각 부재별로 모든 이력단계별 단일한 에너지소산계수를 산정하도록 하고 있어 이력단계에 따른 에너지소산능력의 감소를 고려할 수 없을 것으로 판단된다. 따라서 본 연구에서는 반복하중을 받는 일반보에 대한 기존 실험결과와 비선형시간이력해석 결과를 비교하여 이력단계에 따른 에너지소산계수를 고찰하였다. 에너지소산계수는 비선형시간이력해석 결과로 구한 이상화된 탄소성거동 에너지 소산량에 대한 실제 실험체의 에너지소산량의 비로써 산출하였다. 기존 실험결과는 1회 Cycle을 각 이력단계별로 산정하여 에너지소산계수를 도출하였으며, 지침서 내 비선형모델링 과정을 토대로 에너지소산계수를 도출하였다. 기존 실험연구에선 각 이력단계(Y-L-R)를 설정하여 에너지소산계수를 구하였으며, 에너지소산계수는 Y-L구간 0.36, L-R구간 0.28로 나타났고, 지침서 에너지소산계수는 0.31로 나타났다. 이는 지침서의 에너지소산계수 산정식이 철근콘크리트 부재의 에너지소산능력의 감소를 나타내지 못하는 것으로 나타났다.

As the hysteretic behavior of reinforced concrete members under cyclic loading progresses, the energy dissipation ability decreases due to a decrease in stiffness and strength and pinching effects. However, the guideline "Nonlinear Analysis Model for Performance-Based Seismic Design of Reinforced Concrete Building Structures, 2021" requires calculating a single energy dissipation factor for each member and all histeric step, so the decrease in energy dissipation capacity according to histeric step cannot be considered. It is judged that Therefore, in this study, the energy dissipation factor according to the histeric step was examined by comparing the existing experimental results and the nonlinear time history analysis results for a general beam under cyclic loading. The energy dissipation factor was calculated as the ratio of the energy dissipation amount of the actual specimen to the energy dissipation amount of the idealized elastoplastic behavior obtained as a result of nonlinear time history analysis. In the existing experiment results, the energy dissipation factor was derived by calculating one cycle for each histeric step, and the energy dissipation factor was derived based on the nonlinear modeling process in the guidelines. In the existing experimental study, the energy dissipation factor was calculated by setting each histeric step (Y-L-R), and the energy dissipation factor was found to be 0.36 in the Y-L step and 0.28 in the L-R step, and the energy dissipation factor in the guideline was found to be 0.31. This shows that the energy dissipation factor calculation formula in the guidelines does not indicate a decrease in the energy dissipation capacity of reinforced concrete members.

키워드

참고문헌

  1. Takeda, T., Sozen, M. A., and Nielsen, N. N. (1970), Reinforced concrete response to simulated earthquakes, Journal of the Structural Division, 96(12), 2557-2573. https://doi.org/10.1061/JSDEAG.0002765
  2. Ibarra, L. F., and Krawinkler, H. (2005), Global Collapse of Frame Structures under Seismic Excitations, PEER Report 2005-06. Pacific Earthquake Engineering Research Center, University of California, Berkeley, CA.
  3. Lee, J. Y., and Watanabe, F. (2003), Shear deterioration of reinforced concrete beams subjected to reversed cyclic loading, Structural Journal, 100(4), 480-489. https://doi.org/10.14359/12657
  4. Architectural Institute of Korea, Korea Concrete Institute. (2021), Nonlinear analysis model for performance-based seismic design of reinforced concrete building structures, Korea.
  5. Naish, D., Fry, J. A., Klemencic, R., and Wallace, J. (2009), Experimental evaluation and analytical modeling of ACI 318-05/08 reinforced concrete coupling beams subjected to reversed cyclic loading. Report No. UCLA-SGEL, 6.