• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.912-917
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• 2003

In this paper a new truss modeling technique for describing the beam shear resistance mechanism is proposed based on the reinterpretation of the well-known relationship between shear and the rate of change of bending moment 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 resistance can be gained by viewing the internal stress filed in terms of the superposition of two base components of shear resistance; arch action and beam action. The arch action can be described as a simple tied-arch which is consisted of a curved compression chord and a tension tie of the longitudinal steel, while the beam action between the two chords can be modeled as a membrane shearing element with forming a smeared truss action. The compatibility of deformation associated to the two action is taken into account by employing an experimental factor or internal state force factor a. Then the base equation of V=dM/dx is numerically duplicated. The new model was examined by the 362 experimental results. The shear strength predicted by the internal force state factor a show better correlation with the tested values than the present shear design.

• International Journal of Concrete Structures and Materials
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• 제8권1호
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• pp.1-14
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• 2014

In the present paper, a behavioral model is proposed for study of the individual contributions to shear capacity in shear-critical reinforced concrete members. On the basis of the relationship between shear and bending moment (V = dM/dx) in beams subjected to combined shear and moment loads, the shear resistant mechanism is explicitly decoupled into the base components-beam action and arch action. Then the overall behavior of a beam is explained in terms of the combination of these two base components. The gross compatibility condition between the deformations associated with the two actions is formulated utilizing the truss idealization together with some approximations. From this compatibility condition, the ratio of the shear contribution by the tied arch action is determined. The performance of the model is examined by a comparison with the experimental data in literatures. The results show that the proposed model can explain beam shear behavior in consistent way with clear physical significance.

• 콘크리트학회지
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• 제6권2호
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• pp.180-187
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• 1994

철근콘크리트보에서의 아취작용에 대한 현상을 파악하기 위해 전단지간 대 유효높이의 비 (a/b), 철근비, 전단철근의 유무등을 변수로 하여 총 16개의 시험체를 제작하여 실험하였다. 실험결과, 철근콘크리트보에서 아취현상은 최초로 보에 휨균열이 발생되면서 시작되고, 휨균열이 전단지간 중앙위치까지 발생되면 아취현상이 현저해져 보의 전체적 거동을 지배하는 것으로 나타났다. 철근콘크리트보의 전체적 거동이 아취작용에 이해 주로 지배되면, 전단지간내에서 측정된 철근인장력은 계산된 철근인장력보다 휠씬 크게 나타났다. 철근콘크리트보에서 아취현상은 지점쪽에 가까울수록, 철근비가 낮을수록 헌저하고, 전단보강을 함으로서 아취현상은 작아졌다. 철근콘크리트보에서 아취현상은 a/b가 작아질수록 증가되고, a/b가 3이하에서는 아취현상이 지배적이었다. 전단보강이 안된 a/b가 3이하의 보에서는 최종하중단계에서 타이드 아취현상이 현저하여 철근 길이\ulcorner향에 따른 철근인장력은 거의 동일한 값을 나타냈다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
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• pp.884-889
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• 2003

Based on the reinterpretation of the well-known relationship between shear and the rate of change of bending moment in a reinforced concrete beam subject to combined shear and moment loads, the shortcomings of present truss models are discussed. The core of the theory is that a new perspective on the shear strength can be gained by viewing the internal stress filed in terms of the superposition of two base components of shear resistance; arch action and beam action. The arch action can be designed using the simple truss having curved compression chord, while the beam action between the two chords can be modeled using a parallel chord truss with MCFT or RA-STM. The compatibility of deformation associated to the two action is taken into account by employing a characteristic factor a. The new model was examined by the Stuttgart beam shear tests, and the results show that the present approach provides good estimates of stirrup contribution and concrete contributions.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1993년도 가을 학술발표회 논문집
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• pp.201-206
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• 1993

Four reinforced concrete beams without shear reinforcement were tested statically up to failure to investigate the arch action in reinforced concrete beams. Major variable was the shear span to depth ratio varied from 2 to 4. Due to the reduction of internal moment arm length by the development of arch action, the measured steel tension was higher than the calculated steel tension.

• 한국지진공학회:학술대회논문집
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• 한국지진공학회 1999년도 추계 학술발표회 논문집 Proceedings of EESK Conference-Fall
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• pp.178-185
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• 1999

Six of scaled concrete circular columns were experimentally investigated for the contribution of arch action to the column lateral resistance. For this the specimens with the variation of tranverse hoop steel spacing were tested in absence of axial loading All specimens showed the flexure governing behavior pattern irrelevant to transverse hoop spacing. This indicates that the role of arch action should be understood as the intermediate mechanism causing the interaction between shear and flexural mechanisms A simple truss model was proposed to qualitatively explain this notation but further study is needed to advance its application to general columns.

• 콘크리트학회지
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• 제10권6호
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• pp.233-240
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• 1998

구조역학에 기초한 보의 종방향 휨모멘트변화율과 전단력의 관계와 본 연구자가 이전에 발표한 아취모델을 이용하여 복부보강이 안된 철근콘크리트 보의 전단강도 예측식을 제안하였다. 이론적으로 유도된 본 연구의 전단강도식은 주로 실험결과에 기초한 ACI 318 전단강도식과 비슷한 형태이다. 본 연구에서 제안한 식은 콘크리트 압축강도, 주인장철근비 및 전단지간대 유효높이의 비가 주변수이며, 보작용과 아취작용의 조합에 의한 철근콘크리트 보의 전단저항메카니즘이 합리적으로 반영되어 있다. 본 연구에서 제안한 전단강도식은 ACI 318 전단강도식 및 Zsutty의 전단강도식과 함께 기존의 실험결과와 비교되었다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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• pp.362-365
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• 2006

This paper presents a model for evaluating the contribution by arch action to shear resistance in shear-critical RC beams. Based on the relationship between shear and bending moment in beams subjected to combined shear and bending, The behavior of a beam is explicitly divided into two base components of the flexural action and the tied arch action. The compatibility condition of the shear deformation that deviates from Bernoulli bending plane is formulated utilizing the smeared truss idealization with an inclined compression chord. From this shear compatibility condition in a beam, the shear contribution by the arch action is numerically decoupled.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 가을 학술발표회논문집(I)
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• pp.629-634
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• 2000

In this study, 9 reinforced concrete(RC) continuous beams were tested to investigate the arch action. By measuring longitudinal steel strains during the whole loading stages up to failure, the development of arch action is evaluated. Variables included are span length, longitudinal steel ratio and the presence of stirrups. As a result, it was known that measured steel tension in the span is substantially higher than the conventionally calculated values, and it was appeared that near the middle of the shear span the measured values exceeded the calculated values by factors of up to 1.4 or more.

• 콘크리트학회논문집
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• 제18권3호
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• pp.379-388
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• 2006

본 연구의 목적은 휨과 전단에 지배 받는 철근콘크리트 보에서 아치작용에 의한 전단기여분을 평가하는 모델을 개발하는 것이다. 전단력은 휨모멘트의 변화률이라는 관계식을 기초로, 분산트러스 이상화 기법을 이용하여 횡단면에서 베르누이(Bernoulli) 휨 평면으로부터 전단변형적합조건을 새롭게 유도하였다. MCFT와 분산트러스 이상화를 통해 전단흐름에 의한 복부전단요소의 전단곡률을 일치시키는 전단변형적합조건을 수립하였다. 전단변형적합조건을 이용하면, 보 전단거동은 타이드아치작용과 보 작용의 두 성분으로 수치적 분해 될 수 있다. 그리고 두 기본 작용의 분해가 가능하기 때문에 전단에 지배받는 보의 내력을 예측할 수 있다. 제안 모델의 유효성은 기존 문헌에 수록된 활용 가능한 실험 자료를 통해 검증하였고, 수행 결과는 예측치와 실험치 사이에서 실질적으로 일치하는 결과를 얻었다. 결과의 정확성으로부터 제안 모델의 합리성을 확신할 수 있었다.