• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.7
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• pp.481-492
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• 2018

The steel-plate concrete composite beam is composed of a steel plate, concrete and shear connector to combine two inhomogeneous materials. In general, the steel plate is assembled by welding an existing composite beam. In this study, the SPC beam was composed of folding steel plates and concrete, without a headed stud. The folding steel plate was assembled by a high strength bolt instead of welding. To improve the workability in a field construction, a hat-shaped cap was attached to the junction with a slab. Monotonic load testing under two points was conducted under displacement control mode to analyze the flexural strength of the SPC beam using a cap as the shear connector. Five specimens with shear connector types, protrusion length, and different thickness of steel plates were constructed and tested. The experimental results were analyzed through the relationship between the shear strength ratio and flexural strength in KBC 2009. The test results showed a shear strength ratio of more than 40 %. In the case of using a cap-like specimen as the shear connector, the flexural strength was 70% of the value calculated as a fully composite beam. In addition, the cap showed a smaller shear strength than the stud, but the cap served as a shear connection. When the thickness of the steel plate was taken as a variable, the steel plate exhibited a bending strength of approximately 70% compared to a fully formed steel plate, and exhibited similar deformation performance. Local buckling occurred due to incomplete composite behavior, but local buckling occurred at a 5% higher strength for a relatively thick steel plate. The buckling width also decreased by 15%.

• Steel and Composite Structures
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• v.26 no.4
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• pp.485-499
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• 2018

In this paper, a hollow steel tube (HST) shear connector is proposed for use in a slim-floor system. The HST welded to a perforated steel beam web and embedded in concrete slab. A total of 10 push-out tests were conducted under static loading to investigate the mechanical behavior of the proposed HST connector. The variables were the shapes (circular, square and rectangular) and sizes of hollow steel tubes, and the compressive strength of the concrete. The failure mode was recorded as: concrete slab compressive failure under the steel tube and concrete tensile splitting failure, where no failure occurred in the HST. Test results show that the square shape HST in filled via concrete strength 40 MPa carried the highest shear load value, showing three times more than the reference specimens. It also recorded less slip behavior, and less compressive failure mode in concrete underneath the square hollow connector in comparison with the circular and rectangular HST connectors in both concrete strengths. The rectangular HST shows a 20% higher shear resistance with a longer width in the load direction in comparison with that in the smaller dimension. The energy absorption capacity values showed 23% and 18% improvements with the square HST rather than a headed shear stud when embedded in concrete strengths of 25 MPa and 40 MPa, respectively. Moreover, an analytical method was proposed and predicts the shear resistance of the HST shear connectors with a standard deviation of 0.14 considering the shape and size of the connectors.

• Journal of the Korea institute for structural maintenance and inspection
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• v.10 no.6
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• pp.175-182
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• 2006

In the design of composite structures, shear connectors such as headed stud, channel, perforated plate, etc, are commonly used to transfer longitudinal shear forces across the steel-concrete interface. Many researches have been conducted to improve the characteristics of different types of shear connector. This paper presents the results of 11 push-out tests performed on the new perforated rib connectors with shearing bars embedded in concrete slab under static loads. The results obtained from these tests are as following : 1) The bearing plate welded on both sides of perforated rib plate improves the stiffness and strength. 2) The capacity of perforated connectors is influenced primarily by the transverse reinforcements and shearing bars.

• Composites Research
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• v.21 no.5
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• pp.1-8
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• 2008

In recent years, the reversed L-shaped perforated shear connector has been developed to mitigate the problem associated with headed stud and Perforbond shear connector and to simulate the simultaneous failure of concrete and shear connector. And FRP perforated shear connector has been applied to composite concrete and FRP module in the FRP-concrete composite bridge deck. The design criterion of the reversed L-shaped and FRP perforated shear connector has not been established yet since the lack of experimental and analytical study results. In this paper, the existing design equations for the Perforated were briefly discussed and the equation fur the prediction of shear resisting capacity of the reversed L-shaped and FRP perforated shear connector was suggested based on the experimental test, FEM analysis. and the existing equation for the Perfobond. The predict results obtained by the suggested equation arc compared with the experimental results, the applicability and effectiveness of suggested equation was verified.

• Steel and Composite Structures
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• v.49 no.2
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• pp.215-230
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• 2023

Cable-girder anchorage joint is the critical part of cable-supported bridges. Tensile-plate anchorage (TPA) is one of the most commonly used types of cable-girder anchorage joints in steel girder cable-supported bridges. In recent years, it has been proposed by bridge designers to apply TPA to concrete girder cable-supported bridges to form composite cable-girder anchorage joint (CCGAJ). In this paper, the mechanical performance of CCGAJ under tensile force is studied through experimental and numerical analyses. Firstly, the effects of the external prestressing (EP) and the bearing plate (BP) on the mechanical performance of CCGAJ were investigated through three tests. Then, finite element model was established for parametrical study, and was verified by the experimental results. Then, the effects of shear connector forms, EP, BP, vertical rebar rate, and perforated rebar rate on the tensile capacity of CCGAJ were investigated through numerical analyses. The results show that the tensile capacity of CCGAJ depends on the first row of PR. The failure mode of CCGAJ using headed stud connectors is to form a shear failure surface at the end of the studs while the failure mode using PBLs is similar to the bending of a deep girder. Finally, based on the strut-and-tie model (STM), a calculation method for CCGAJ tensile capacity was proposed, which has a high accuracy and can be used to calculate the tensile capacity of CCGAJ.

• Journal of The Korean Society of Grassland and Forage Science
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• v.40 no.1
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• pp.44-49
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• 2020

This study was conducted to investigate the possibility of replacing imported Timothy hay (TH) with domestic Italian ryegrass silage (IRGS) as a horse feed considering feed quality, nutrient digestibility and feed price. Two experimental diets (TH and IRGS) were fed to six-headed Thoroughbred (body weight, 475.7±33.3kg) of the Korea Racing Authority of Wondang Stud Farm. The 3 head animals were assigned to Control group (TH) and Treatment group (IRGS), respectively. The nutrient digestibility was determined by the total collection method. IRGS is enough for using as a horse feed because its Relative feed value(RFV) was higher than TH and its fermentation quality is suitable for horses. Although no difference was observed in nutrient digestibility, Total digestible nutrients(TDN), and Digestible energy(DE) between Control and Treatment group (p>0.05), the fact that price of IRGS was much lower (53.7~62.4%) than that of TH indicates IRGS has competitive advantage over TH as a horse forage feed. The present study indicates that IRGS can be fully replaced with TH due to its superior economic value even though the similarity of its nutrient digestibility, TDN, and DE to TH.