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2019 Vol.32, Issue 6 Preview Page

Research Paper

Non-linear Dynamic Analysis of Reinforced Concrete Slabs Subjected to Explosive Loading Using an Orthotropic Concrete Constitutive Model

이등방성 콘크리트 모델을 이용한 폭발하중을 받는 철근콘크리트 슬래브의 비선형 동적해석

MinJoo Lee1
,
Hyo-Gyoung Kwak2†
이 민 주1
,
곽 효 경2†
1Graduate Student, Division of Civil and Environmental Engineering, KAIST, Daejeon, 34141, Korea
2Professor, Division of Civil and Environmental Engineering, KAIST, Daejeon, 34141, Korea
1한국과학기술원 건설 및 환경공학과 박사과정
2한국과학기술원 건설 및 환경공학과 교수
†Corresponding author: Tel: +82-42-350-3621; E-mail: kwakhg@kaist.ac.kr
31 December 2019. pp. 409-416
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Abstract

An improved numerical model for non-linear analysis of reinforced concrete (RC) slabs subjected to blast loading is proposed. This approach considers a strain rate dependent orthotropic constitutive model that directly determines the stress state using the stress-strain relation acquired from the data obtained using the biaxial strength envelope. Moreover, the bond-slip between concrete and reinforcing steel is gradually enlarged after the occurrence of cracks and is concentrated in the plastic hinge region. The bond-slip model is introduced to consider the crack direction of the concrete under a biaxial stress state. Correlation studies between the numerical analysis and the experimental results were performed to evaluate the analytical model. The results show that the proposed model can effectively be used in dynamic analyses of reinforced concrete slab members subjected to explosive loading. Moreover, it was determined that it is important to consider biaxial behavior in the material model and the bond-slip effect.

Keywords
orthotropic constitutive model
strain rate effect
bond-slip
dynamic analysis

본 논문에서는 폭발하중을 받는 철근콘크리트 슬래브의 비선형 해석을 위한 개선된 수치 모델을 제안한다. 제안된 모델은 2축 응력 상태를 반영한 등가 강도에 의해 정의된 응력-변형률 관계를 사용하여 응력 상태를 직접 결정하는 변형률 속도 의 존 이등방성 구성 모델을 다룬다. 또한, 균열 발생 후 콘크리트와 철근 사이의 부착 슬립이 점차 확대되어 소성힌지 영역으 로 집중된다. 2축 응력 상태에서 콘크리트의 균열 방향은 주응력 방향에 따라 달라지므로 이를 고려한 부착 슬립 모델을 해 석에 도입하였다. 해석 모델의 검증을 위해 수치해석과 실험결과의 상관관계 연구(correlation studies)가 수행되었다. 해석 결과는 재료모델의 2축 거동과 부착 슬립의 영향을 고려하는 것이 해석결과의 정확성 향상에 중요함을 보여주며 제안된 해 석 모델이 철근콘크리트 슬래브 부재의 폭발해석에 효과적으로 사용될 수 있음을 확인하였다.

키워드
이등방성 구성 모델
변형률 속도 영향
부착 슬립
동적 해석
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Information
  • Publisher :Computational Structural Engineering Institute of Korea
  • Publisher(Ko) :한국전산구조공학회
  • Journal Title :Journal of the Computational Structural Engineering Institute of Korea
  • Journal Title(Ko) :한국전산구조공학회 논문집
  • Volume : 32
  • No :6
  • Pages :409-416
  • Received Date : 2019-10-29
  • Revised Date : 2019-11-26
  • Accepted Date : 2019-11-30
  • DOI :https://doi.org/10.7734/COSEIK.2019.32.6.409
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