전단슬립 효과를 고려한 합성보의 유효강성

허병욱,배규웅,문태섭,Heo, Byung Wook,Bae, Kyu Woong,Moon, Tae Sup 한국강구조학회 2004 韓國鋼構造學會 論文集 Vol.16 No.5

본 연구는 부분 전단연결을 가지는 강-콘크리트 합성보의 처짐에 미치는 전단슬립의 영향을 조사하는 것이다. 현재 각국의 설계규준에서는 합성보의 처짐 계산시 전단연결재의 강도와 관련되어 있지만, 본 연구에서는 하중조건에 상관없는 전단연결재의 강성에 기반을 둔 정확한 해를 유도하였다. 우선, 평형조건, 곡률의 적합조건에 기반을 둔 3가지 하중조건에서의 합성보의 등가강성을 유도하고, 이로부터 하중조건에 상관없이 슬립의 영향을 적용할 수 있는 간편한 제안식을 유도하였다. 이러한 제안식의 타당성을 검증하기 위해서 현재 AISC에서 사용하고 있는 합성보의 유효강성 및 Nie가 제안한 식과 비교하였다. 일반적으로 사용되는 보의 경우, 전단슬립의 영향은 스팬이 짧을 경우, AISC에 비해서 최대 18%까지의 강성의 감소를 나타냄을 알 수 있었다. 완전합성보의 경우, AISC의 제안 값이 본 연구의 결과 보다 크게 나타났는데, 이는 안전측이 되지 못함을 알 수 있었으며, 불완전 합성보의 경우, AISC 제안식이 본 연구보다 강성을 과소 평가하는 결과를 나타내었다. This study investigated the effects of a shear slip on the deflection of steel-concretecomposite beams with partial shear interaction. Under the guidance of various current design codes, this deflection was related to the strength of shear connectors in the composite beams. In this paper, a shear connector stiffness based on exact solutions, regardless of loading conditions, was developed. The equivalent rigidity of composite beams that considered three different loading types was first derived, based on equilibrium and curvature compatibility, from which a general formula accounting for slips was developed. To validate this approach, the predicted maximum deflection under the proposed method was compared against currently used equations to calculate beam effective stiffness (AISC)Nie's equations, which have recently been proposed. For typical beams that were used in practice, shear slips might result in stiffness reduction of up to 18% for short-span beams. For full composite sections, the effective section modulus with the AISC specifications was larger than that of the present study, which meant that the specifications were not conservative. For partial composite sections, the AISC predictions were more conservative than those in the present study.

매입형 합성보의 휨 성능 평가 -속 빈 프리캐스트 콘크리트 슬래브와 비대칭 H형강 철골보-

허병욱,배규웅,문태섭,Heo, Byung Wook,Bae, Kyu Woong,Moon, Tae Sup 한국강구조학회 2004 韓國鋼構造學會 論文集 Vol.16 No.5

본 연구에서는 합성보의 전체 춤을 절감할 수 있도록 속 빈 프리캐스트 콘크리트 슬래브를 철골보의 춤내에 삽입하여 일체화함으로써 철골조 고층건물에서 층고를 최소화 할 수 있는 이른바 "슬림플로어"공법에 대한 연구를 수행하였다. 본 연구는 콘크리트에 매입된 비대칭 철골보를 가지는 불완전 합성 슬림플로어 시스템의 휨 거동에 관한 것이다. 총 10개의 실대형 실험체를 철골보 춤, 속빈 프리캐스트 콘크리트 슬래브 춤, 슬래브 유효폭, 및 콘크리트 슬래브의 지지방식 별로 제작하여 실험을 수행하였다. 실험결과, 매입형 합성보의 경우, 별도의 전단연결재를 설치하지 않아도 자체가 가지고 있는 기계적 화학적 부착응력으로 인해 완전합성보에 비해서 0.48~0.98의 전단합성비를 나타내었다. In this study, an experiment was conducted on the Slim Floor system, using a hollow core PC slab, which could reduce the over-all depth of a composite beam. The Slim Floor system is a method used in steel frame multi-story building construction, in which the structural depth of each floor is minimized after incorporating the steel floor beams within the depth of the concrete floor slab. This experimental study focused on the flexural behavior of the partially connected Slim Floor system with asymmetric steel beams encased in hollow core PC slabs. Ten full-scale specimens were constructed and tested in this study, with different steel beam heights, hollow core PC slabs, slab widths, and PC slab bearings. Observations made in line with the experiments indicated that the degree of shear connection without additional shear connection was 0.48-0.98 times more than that of the full shear connection, due to inherent mechanical and chemical bond stress.

매립형 불완전 합성보의 휨 거동 예측

허병욱,배규웅,문태섭,Heo, Byung Wook,Bae, Kyu Woong,Moon, Tae Sup 한국강구조학회 2004 韓國鋼構造學會 論文集 Vol.16 No.6

강-콘크리트 합성보에서 강과 콘크리트 사이의 불완전 합성거동은 완전 합성보에 비해서 처짐이 매우 증가하게 된다. 특히, 춤이 깊은 데크 및 속 빈 PC슬래브 등을 사용한 매립형 합성보의 경우, 자체의 형상에 기인하여 처짐에 매우 취약하다. 본 연구에서는 기존 연구에서 유도한 슬립효과를 고려한 처짐 계산법 및 실험으로부터 구한 하중-슬립 관계로부터 매립형 합성보의 전단부착응력 및 슬립에 의한 추가 처짐 값을 제시하였다. 매립형 합성보의 처짐에 미치는 슬립의 영향은 완전 합성보의 강성 값에 비해 약 30%정도 감소함을 알 수 있었다. 또한, 실험 및 예측 값의 비교결과, 6%내외의 오차로 비교적 좋은 결과를 나타내었다. With steel and concrete composite beams, the incomplete interaction between the steel and the concrete slab leads to an appreciable increase in beam deflections. Moreover, encased composite beams using a deep deck plate or hollow-core PC slabs are critical to deflection due to their inherent geometry. In this paper, by using the calculation tools that were developed for a previous study on the deflection of encased composite beams considering the slip effects and load-slip curve, the shear bond stress and additional deflection induced due to interface slip of the encased composite beam are presented. It was found that the slip effects significantly contribute to the encased composite beam deflections and result in stiffness reduction of up to 30% compared to that of full shear interaction beams. The predicted results were compared with the measurement of 18 specimens tested in this study, and comparisons show a high degree of accuracy, within 6%.

불완전 합성보의 유효강성 평가방법 비교

허병욱,배규웅 대한건축학회 2006 大韓建築學會論文集 : 構造系 Vol.22 No.11

Previously study, An exact solution based on the stiffness of shear connectors was developed which is not dependent on the load cases. The equivalent rigidity of composite beams considering three different loading types was first derived based on equilibrium and curvature compatibility, from which a general formula to account for slip effects was developed. To validate this approach, the predicted maximum deflection using the proposed method is compared against currently used equations for the calculation of the beam effective stiffness. For typical beams used in practice, shear slip effects may results in stiffness reduction up to 18% for short span beams. For full composite sections, the effective stiffness with the AISC specifications are larger than that of present study, meaning that the specifications are not on the conservation side. For partial composite sections, the AICS predictions are more conservative than the present study.

강-콘크리트 불완전 합성보의 처짐평가

허병욱,곽명근,배규웅 大韓建築學會 2007 大韓建築學會論文集 : 構造系 Vol. No.

<P>The present study investigates the effects of shear slip on deflection of steel-concrete composite beams with partial shear interaction. According to the various current design codes, the deflection is related to the strength of shear connectors in the composite beams. However, the decrease of stiffness due to slip effects are not considered in the current design codes and relevant calculation tools for partial shear connection are not even presented. In previous study, It is derived an exact solution based on the stiffness of shear connectors which is not dependent on the load cases. The equivalent rigidity of composite beams considering three different loading types was first derived based on equilibrium and curvature compatibility, from which a general formula to account for slip effects was developed. To validate this approach, the predicted maximum deflection using the proposed method and currently used equations for the calculation of the beam effective stiffness is compared against test results. From the comparison between test results and analytical study, it is found that the stiffness of a composite beam based on the strength of shear studs is considerably over-estimated. The stiffness of composite beams is predicted accurately with the method proposed in this study.</P>

전단슬립 효과 및 하중조건을 고려한 불완전 합성보의 유효강성

허병욱,배규웅 대한건축학회 2006 大韓建築學會論文集 : 構造系 Vol.22 No.11

The present study investigates the effects of shear slip on deflection of steel-concrete composite beams with partial shear interaction. According to the various current design codes, the deflection is related to the strength of shear connectors in the composite beams. However, the decrease of stiffness due to slip effects is not considered in the current design codes and relevant calculation tools for partial shear connection are not even presented. In this paper, an exact solution based on the stiffness of shear connectors is developed which is not dependent on the load cases. The equivalent rigidity of composite beams considering three different loading types was first derived based on equilibrium and curvature compatibility, from which a general formula to account for slip effects was developed.

전단슬립 효과를 고려한 매입형 불완전 합성보의 휨거동

허병욱 대한건축학회 2007 大韓建築學會論文集 : 構造系 Vol.23 No.7

The advantages of composite construction are now well understood in terms of structural economy, good performance in service, and ease of construction. However, these conventional composite construction systems have some problems to apply steel framed buildings due to their large depth. Slim Floor system is a method of steel frame multi-story building construction in which the structural depth of each floor is minimised by incorporating the steel floor beams within the depth of the concrete floor slab. Previous study we executed an experimental test with “Slim Floor” system using hollow core PC slab and deep deck plate which could reduce the overall depth of composite beam. Presented herein is an analytical study that focuses on flexural behaviour of the partially connected slim floor system with asymmetric steel beams encased in slabs. From the comparison between the analytical study and the test results, It showed a good agreement with respect to the stiffness reduction due to shear slip. Finally, an equations to predict the load-deflection relationship of encased composite beam are presented.

매입형 불완전 합성보의 휨거동에 대한 해석적 연구

허병욱,신현섭,배규웅 대한건축학회 2007 大韓建築學會論文集 : 構造系 Vol.23 No.6

With steel and concrete composite beams, the incomplete interaction between the steel and the concrete slab leads to an appreciable increase in beam deflections. Moreover, encased composite beams using a deep deck plate or hollow-core PC slabs are critical to deflection due to their inherent geometry. In this paper, by using the calculation tools that were developed for a previous study on the deflection of encased composite beams considering the slip effects and load-slip curve, the shear bond stress and additional deflection induced due to interface slip of the encased composite beam are presented. It was found that the slip effects significantly contribute to the encased composite beam deflections and result in stiffness reduction of up to 30% compared to that of full shear interaction beams. The predicted results were compared with the measurement of 18 specimens tested in this study, and comparisons showed a high degree of accuracy, within 6%.

신개발된 평데크플레이트(ACE-DECk)를 이용한 합성술래브의 전단거동에 관한 실험적 연구

허병욱,양명숙,배규웅,오상훈,Heo, Byung-wook,Yang, Myung-Sook,Bae, Kyu-woong,Oh, Sang-Hoon 한국강구조학회 2001 韓國鋼構造學會 論文集 Vol.13 No.3

구조용 데크플레이트를 사용한 합성슬래브의 파괴형식 중에서 수평전단파괴는 가장 일반적인 파괴형태로써, 본 논문에서는, 데크 춤 60mm인 신개발된 (ACE-DECK) 합성구조용 평데크플레이트를 개발하여 합성슬래브의 전단거동에 관한 실험적 연구를 수행하였다. 실험체는 데크의 형상, 두께 및 콘크리트의 토핑두께를 변수로 하여 총 22개의 실험체를 제작하여 전단부착성능 실험을 실시하였다. 실험결과, 데크의 두께 및 콘크리트 토핑두께에 따른 합성슬래브의 전단부착성능은 크게 영향이 없는 것으로 나타났고, 신형상(ACE-DECK)의 평데크플레이트는 전단부착응력이 $3.6kgf/cm^2$ 까지 나타나 기존의 평데크 형상에 비교하여 효과적인 전단부착성능을 발휘함을 알 수 있었다. Longitudinal shear failure is the most common failure-type in composite slabs. In this paper, the shear-connection behavior of composite slabs with a particular profiled steel sheeting, so called ACE-DECK, having a depth of 60mm is studied experimentaly. Twenty two pull-out test specimens of different shapes, concrete topping thickness, and different steel sheeting thickness are carried out. It is founded that the shear connection behavior of composite slabs are not affected significantly in the steel sheeting thickness and concrete topping thickness. A new type of profiled steel sheeting is more effective in shear-bond strength that of existing flat-type deck plate, which can offer longitudinal shear strength in composite slope up to $3.6kgf/cm^2$

강-콘크리트 불완전 합성보의 처짐평가

허병욱,곽명근,배규웅 대한건축학회 2007 大韓建築學會論文集 : 構造系 Vol.23 No.9

The present study investigates the effects of shear slip on deflection of steel-concrete composite beams with partial shear interaction. According to the various current design codes, the deflection is related to the strength of shear connectors in the composite beams. However, the decrease of stiffness due to slip effects are not considered in the current design codes and relevant calculation tools for partial shear connection are not even presented. In previous study, It is derived an exact solution based on the stiffness of shear connectors which is not dependent on the load cases. The equivalent rigidity of composite beams considering three different loading types was first derived based on equilibrium and curvature compatibility, from which a general formula to account for slip effects was developed. To validate this approach, the predicted maximum deflection using the proposed method and currently used equations for the calculation of the beam effective stiffness is compared against test results. From the comparison between test results and analytical study, it is found that the stiffness of a composite beam based on the strength of shear studs is considerably over-estimated. The stiffness of composite beams is predicted accurately with the method proposed in this study.