Journal of the Computational Structural Engineering Institute of Korea (한국전산구조공학회논문집)

Computational Structural Engineering Institute of Korea (한국전산구조공학회)
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Numerical Model to Evaluate Resistance against Direct Shear Failure and Bending Failure of Reinforced Concrete Members Subjected to Blast Loading

폭발하중을 받는 철근콘크리트 부재의 직접전단 파괴 및 휨 파괴 저항성능 평가를 위한 수치해석 모델 개발

  • Ju, Seok Jun (Department of Civil and Environmental Engineering, KAIST) ;
  • Kwak, Hyo-Gyoung (Department of Civil and Environmental Engineering, KAIST)
  • 주석준 (한국과학기술원 건설및환경공학과) ;
  • 곽효경 (한국과학기술원 건설및환경공학과)
  • Received : 2021.10.01
  • Accepted : 2021.11.03
  • Published : 2021.12.31
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Abstract

In this paper, we proposed a numerical model based on moment-curvature, to evaluate the resistance of reinforced concrete (RC) members subjected to blast loading. To consider the direct shear failure mode, we introduced a dimensionless spring element based on the empirical direct shear stress-slip relation. Based on the dynamic increase factor equations for materials, new dynamic increase factor equations were constructed in terms of the curvature rate for the section which could be directly applied to the moment-curvature relation. Additionally, equivalent bending stiffness was introduced in the plastic hinge region to consider the effect of bond-slip. To verify the validity of the proposed model, a comparative study was conducted against the experimental results, and the superiority of this numerical model was confirmed through comparison with the analytical results of the single-degree of freedom model. Pressure-impulse (P-I) diagrams were produced to evaluate the resistance of members against bending failure and direct shear failure, and additional parametric studies were conducted.

본 논문에서는 폭발하중을 받는 부재의 저항성능 평가를 위한 모멘트-곡률 관계 기반 수치해석 기법을 소개한다. 직접전단 파괴 모드를 고려하기 위하여 경험적인 직접전단응력-슬립양 관계를 기반으로 하는 무차원 스프링 요소를 도입하였다. 재료에 대해 정의된 동적증가계수 식을 바탕으로 단면의 모멘트-곡률 관계에 직접적으로 적용가능한 단면의 곡률 변화율에 따른 동적증가계수 식을 제작하였다. 또한 부착슬립의 영향을 고려하기 위하여 소성힌지영역 내에 등가 휨강성을 도입하였다. 제안된 수치해석 모델의 타당성 검증을 위하여 실험결과와의 비교연구를 수행하였으며, 단자유도계 모델의 해석결과와의 비교를 통해 본 수치해석 모델의 우수성을 확인하였다. P-I 선도를 제작하여 부재의 휨 파괴 및 직접전단 파괴에 대한 저항성능을 평가하였으며, 매개변수 연구를 수행하여 P-I 선도 및 저항성능의 변화를 확인하였다.

Keywords

Acknowledgement

본 연구는 국토교통부 건설기술연구사업(과제번호:21SCIP-B146646-04)의 연구비 지원에 의해 수행되었습니다.

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