• Steel and Composite Structures
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• 제44권5호
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• pp.741-752
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• 2022

Earlier works have shown that excessive shear stiffness at the steel-concrete interface causes a non-uniform distribution of shear force in composite structures. When the shear studs are wrapped at the fixed end with flexible materials with a low elastic modulus, the shear stiffness at the interface is reduced. The objective of this study was to investigate the effect of silicone rubber-sleeve mounted on shear studs on the shear stiffness of steel-concrete composite structures. Eighteen push-out tests were conducted to investigate the mechanical behavior of silicone rubber-sleeved shear stud groups (SRS-SSG). The dimension and arrangement of silicon rubber-sleeves (SRS) were taken into consideration. Test results showed that the shear strength of SRS-SSG was higher than that of a shear stud group (SSG), without SRS. For SRS-SSG with SRS heights of 50 mm, 100 mm, 150 mm, the shear strengths were improved by 13%, 20% and 9%, respectively, compared to the SSG alone. The shear strengths of SRS-SSG with the SRS thickness of 2 mm and 4 mm were almost the same. The shear stiffness of the SRS-SSG specimens with SRS heights of 50 mm, 100 mm and 150 mm were 77%, 67% and 66% of the SSG specimens, respectively. Test results of specimens SSG-1 and predicted values based on the three design specifications were compared. The nominal single stud shear strength of SSG-1 specimens was closest to that calculated by the Chinese Code for Design of Steel Structures (GB50017-2017). An equation is proposed to consider the effects of SRS for GB50017-2017, and the predicted values based on the proposed equation agree well with the tested results of SRS-SSG.

• 한국구조물진단유지관리공학회 논문집
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• 제19권2호
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• pp.108-116
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• 2015

이 연구에서는 SC 전단벽의 전단 연결재인 스터드의 배치와 형상이 SC 전단벽의 거동에 미치는 영향을 살펴보기 위해 전단벽체가 전단력과 축하중, 휨모멘트 및 전단력의 조합하중을 받을 때의 거동을 해석적으로 검토하였다. 이를 위해 서로 다른 배치간격과 형상의 스터드가 배열된 SC 전단벽을 대상으로 유한요소해석을 수행하였다. 강판과 콘크리트가 설계기준에 맞게 잘 합성된 SC 벽체에서 인장강도에 비해 압축강도가 약 3배정도 컸다. 유한요소법으로 SC 전단벽의 조합하중에 대한 거동을 수치해석하여 설계기준과 비교한 결과, 이들 모두 설계강도를 상회하는 결과를 나타내었다. KEPIC SNG의 경우, 축하중강도의 0.1~0.2배 수준의 축하중에는 영향이 없었으나 해석결과는 축하중이 증가할수록 모멘트와 전단강도가 감소함을 확인하였다.

• Steel and Composite Structures
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• 제38권4호
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• pp.431-445
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• 2021

This paper presents experiments and theoretical analysis on shear behavior of eight concrete-encased square concrete-filled steel tube (CECFST) specimens and three traditional reinforced concrete (RC) specimens. A total of 11 specimens with the test parameters including the shear span-to-depth ratio, steel tube size and studs arrangement were tested to explore the shear performance of CECFST specimens. The failure mode, shear capacity and displacement ductility were thoroughly evaluated. The test results indicated that all the test specimens failed in shear, and the CECFST specimens enhanced by the interior CFST core exhibited higher shear capacity and better ductility performance than that of the RC specimens. When the other parameters were the same, the larger steel tube size, the smaller shear span-to-depth ratio and the existence of studs could lead to the more satisfactory shear behavior. Then, based on the compatible truss-arch model, a set of formulas were developed to analytically predict the shear strength of the CECFST members by considering the compatibility of deformation between the truss part, arch part and the steel tube. Compared with the calculated results based on several current design specifications, the proposed formulas could get more accurate prediction.

• Steel and Composite Structures
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• 제35권2호
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• pp.261-278
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• 2020

In steel-concrete composite beams, to improve the cracking resistance of the concrete slab in the hogging moment region, a new type of connector in the interface, named uplift-restricted and slip-permitted screw-type (URSP-S) connector has been proposed. This paper focuses on the behavior of steel-concrete composite beams with URSP-S connectors. A total of three beam specimens including a simply supported beam with URSP-S connectors and two continuous composite beams with different connectors arrangements were designed and tested. More specifically, one continuous composite beam was equipped with URSP-S connectors in negative moment region and traditional shear studs in other regions. For comparison, the other one was designed with only traditional shear studs. The failure modes, crack evolution process, ultimate capacities, strain responses at different locations as well as the interface slip of the three tested specimens were measured and evaluated in-depth. Based on the experimental study, the research findings indicate that the larger slip deformation is allowed while using URSP-S connectors. Meanwhile, the tensile stress reduces and the cracking resistance of the concrete slab improves accordingly. In addition, the overall stiffness and strength of the composite beam become slightly lower than those of the composite beam using traditional shear studs. Moreover, the arrangement suggestion of URSP-S connectors in the composite beam is discussed in this paper for its practical design and application.

• Steel and Composite Structures
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• 제36권1호
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• pp.1-16
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• 2020

In steel-concrete composite beams, to improve the cracking resistance of the concrete slab in the hogging moment region, a new type of connector in the interface, named uplift-restricted and slip-permitted screw-type (URSP-S) connector has been proposed. This paper focuses on the behavior of steel-concrete composite beams with URSP-S connectors. A total of three beam specimens including a simply supported beam with URSP-S connectors and two continuous composite beams with different connectors arrangements were designed and tested. More specifically, one continuous composite beam was equipped with URSP-S connectors in negative moment region and traditional shear studs in other regions. For comparison, the other one was designed with only traditional shear studs. The failure modes, crack evolution process, ultimate capacities, strain responses at different locations as well as the interface slip of the three tested specimens were measured and evaluated in-depth. Based on the experimental study, the research findings indicate that the larger slip deformation is allowed while using URSP-S connectors. Meanwhile, the tensile stress reduces and the cracking resistance of the concrete slab improves accordingly. In addition, the overall stiffness and strength of the composite beam become slightly lower than those of the composite beam using traditional shear studs. Moreover, the arrangement suggestion of URSP-S connectors in the composite beam is discussed in this paper for its practical design and application.

• Nuclear Engineering and Technology
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• 제56권1호
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• pp.78-91
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• 2024

Double steel plate concrete composite shear wall (SCSW) has been widely utilized in nuclear power plants and high-rise structures, and its shear connectors have a substantial impact on the seismic performance of SCSW. Therefore, in this study, the mechanical properties of SCSW with angle stiffening ribs as shear connections were parametrically examined for the reactor containment structure of nuclear power plants. The axial compression ratio of the SCSW, the spacing of the angle stiffening rib arrangement and the thickness of the angle stiffening rib steel plate were selected as the study parameters. Four finite element models were constructed by using the finite element program named ABAQUS to verify the experimental results of our team, and 13 finite element models were established to investigate the selected three parameters. Thus, the shear capacity, deformation capacity, ductility and energy dissipation capacity of SCSW were determined. The research results show that: compared with studs, using stiffened ribs as shear connectors can significantly enhance the mechanical properties of SCSW; When the axial compression ratio is 0.3-0.4, the seismic performance of SCSW can be maximized; with the lowering of stiffener gap, the shear bearing capacity is greatly enhanced, and when the gap is lowered to a specific distance, the shear bearing capacity has no major affect; in addition, increasing the thickness of stiffeners can significantly increase the shear capacity, ductility and energy dissipation capacity of SCSW. With the rise in the thickness of angle stiffening ribs, the improvement rate of each mechanical property index slows down. Finally, the shear bearing capacity calculation formula of SCSW with angle stiffening ribs as shear connectors is derived. The average error between the theoretical calculation formula and the finite element calculation results is 8% demonstrating that the theoretical formula is reliable. This study can provide reference for the design of SCSW.

• 한국구조물진단유지관리공학회 논문집
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• 제8권4호
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• pp.231-238
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• 2004

본 논문은 스터드를 사용한 철근콘크리트 부재와 철골 부재의 접합부의 인장거동에 관한 연구를 나타내었다. 스터드 접합부의 인장 및 휨 성능을 향상시키기 위하여 행거를 스터드 주위에 설치하였다. 행거로 보강된 스터드 접합부의 인장 성능을 평가하기 위하여 철근비, 행거 상세, 묻힘길이 등을 변수로 한 8 개의 실험체를 계획하였다. 인장실험을 통하여 행거 보강이 접합부의 인장강도를 증가시키는데 매우 효과적인 것을 알 수 있었다. 기준식에 의한 인장강도 평가로부터 CCD식이 강도 산정에 보다 적합한 것으로 나타났다.

• 한국강구조학회 논문집
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• 제19권3호
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• pp.303-312
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• 2007

경간 40m~100m 정도 경간에 대해 일반적으로 강 박스 거더교에 대한 설계가 이루어지고 있다. 상부구조의 자중을 줄이기 위해서 복합트러스 교량에서 복부의 콘크리트 웹 대신에 강 사재가 사용되고 있다. 이러한 복합트러스 교량의 설계 시 가장 중요한 부분 중의 하나가 콘크리트 상 하부를 연결하는 연결부의 형태이다. 이러한 접합부는 외부에서 작용하는 조합하중을 분담해야하는데, 아직 이러한 접합구조에 대한 명확한 설계기준이 없는 실정이다. 한계상태에서 격점부의 하중전달에 대한 명확한 연구와 설계방법에 대한 조사가 필요하다. 콘크리트 상 하부를 연결하는 격점부 사재는 다양한 연결형태가 있다. 이번 논문에서는 거셋 플레이트에 용접되어진 그룹 스터드 연결재에 관한 연구가 수행되었다. 25mm 절곡 스터드를 사용하여 수행된 전단실험을 통하여 현재의 스터드 간 최소기준 간격을 만족하는 상태에서는 현재의 설계 규정을 사용할 수 있음을 밝혔다. 휨-전단 실험을 통해서는 조합하중이 작용하는 격점부의 상세를 개선하였다. 격점부의 인발강도를 증진시키기 위해서 절곡 스터드가 제안되었고 그룹 스터드의 최 외측 스터드에 적용되었다. 이러한 결과들을 바탕으로 복합 트러스 교량의 개선된 격점부 상세가 개선되고 설계 방안이 제안되었다.

• Steel and Composite Structures
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• 제17권3호
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• pp.237-252
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• 2014

The use of composite structures is increasingly present in civil building works. Composite Box Girder Bridges (CBGB), particularly, are study of effect of shear connector's numbers and distribution on the behavior of CBGBs is submitted. A Predicti structures consisting of two materials, both connected by metal devices known as shear connectors. The main functions of these connectors are to allow for the joint behavior of the girder-deck, to restrict longitudinal slipping and uplifting at the element's interface and to take shear forces. This paper presents 3D numerical models of CBGBs to simulate their actual structural behavior, with emphasis on the girder-deck interface. Additionally, a Prediction of several FE models is assessed against the results acquired from a field test. A number of factors are considered, and confirmed through experiments, especially full shear connections, which are obviously essential in composite box girder. A good representation for shear connectors by suitable element type is considered. Numerical predictions of vertical displacements at critical sections fit fairly well with those evaluated experimentally. The agreement between the FE models and the experimental models show that the FE model can aid engineers in design practices of box girder bridges. Preliminary results indicate that number of shear studs can be significantly reduced to facilitate adoption of a new arrangement in modeling CBGBs with full composition. However, a further feasibility study to investigate the practical and economic aspects of such a remedy is recommended, and it may represent partial composition in such modeling.

• Steel and Composite Structures
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• 제34권6호
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• pp.837-851
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• 2020

This study aims to examine the interface shear behavior between precast high-strength concrete slabs with pockets and steel beam to achieve accelerated bridge construction (ABC). Twenty-six push-out specimens, with different stud height, stud diameter, stud arrangement, deck thickness, the infilling concrete strength in shear pocket (different types of concrete), steel fiber volume of the infilling concrete in shear pocket concrete and casting method, were tested in this investigation. Based on the experimental results, this study suggests that the larger stud diameter and higher strength concrete promoted the shear capacity and stiffness but with the losing of ductility. The addition of steel fiber in pocket concrete would promote the ductility effectively, but without apparent improvement of bearing capacity or even declining the initial stiffness of specimens. It can also be confirmed that the precast steel-concrete composite structure can be adopted in practice engineering, with an acceptable ductility (6.74 mm) and minor decline of stiffness (4.93%) and shear capacity (0.98%). Due to the inapplicability of current design provision, a more accurate model was proposed, which can be used for predicting the interface shear capacity well for specimens with wide ranges of the stud diameters (from13 mm to 30 mm) and the concrete strength (from 26 MPa to 200 MPa).