• Journal of Korean Society of Steel Construction
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• v.23 no.2
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• pp.229-236
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• 2011

This study was conducted to understand the characteristics of the compression behavior of steel plate-concrete(SC) structures with a width-to-thickness ratio under axial loading. SC structures are structural systems where concrete is poured into steel plates to which headed stud bolts had been attached inside. The specimens were classified according to the two width-to-thickness (W/T) ratios of 1.60 and 3.56. Through these experiments, the following conclusions could be arrived at. The fracture pattern of the specimens showed that steel plate buckling occurred between the stud lines, and that a crack occurred at the concrete spalling from the sides of the concrete before the system reached the maximum compressive strength. The maximum compressive strength of the specimens was larger than that of the existing equations (AISC 2005, ACI 318-05, and KBC 2005). With the increased W/T ratio of the specimens, the strength of the concrete core was decreased to account for the confinement effects from the steel plates.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.6A
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• pp.651-659
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• 2009

This study dealt with the behavior of pile-abutment joints in integral abutment bridges. Two types of pile-abutment joints were proposed to strengthen its rigid action. One was fabricated with transverse rebars which penetrated the H-pile in the abutment. The other was composed of stud shear connectors on the flanges of the H-pile. Three half scaled pile-abutment joint specimens were fabricated and loading tests were performed to evaluate the behavior of proposed joints. The results showed that the initial stiffness in elastic region of all specimens was sufficient to be applied for the integral abutment bridges. However, the performances of the proposed joints were shown to be more effective in rigid action compared to the joints types suggested by the Integral Bridge Design Guideline. The results from stiffness, strength, rotation and crack propagation tests supported this matter.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.4 s.97
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• pp.122-128
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• 1999

Bolted joint assembly for nuclear power plants consists of various components : cover plate, retainer plate, manway flange, gasket and stud bolts/nuts. To guarantee the soundness of the joint, it is important to prevent leakage through the gasket and reduce the stress concentration factor at the thread root. In this paper, Submodeling technique for the finite element method is proposed to accurately compute three dimensional contact stresses which govern the sealing performance and the maximum contact stresses at the threads root. For verification of global solutions used as boundary conditions of submodel solution, the stresses on the cover plate and the manway flange are measured by strain gages when internal pressure is applied to the bolted joint assembly. The numerical results are compared with the experimental results.

• Journal of Korean Society of Steel Construction
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• v.18 no.4
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• pp.405-416
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• 2006

In composite girders with steel embedded in concrete as preflex beams, horseshoe connectors and bar connectors are commonly used to achieve composite action. Considering the requirements on the concrete cover in the thin concrete part surrounding a steel member, it has limitations with respect to the use of stud shear connectors, and significant bond and friction resistance can be generated. High horizontal shear strength between the casing concrete and the steel section is needed to introduce prestress to the concrete section in the form of preflex beams.In this paper, experiments on the evaluation of the static strength of horseshoe connectors and bar connectors were conducted and the effects of bonds were also considered. Based on the test results, current design codes were estimated and more general design guidelines that consider the design concept of Eurocode were proposed for the connectors. A strength evaluation according to failure and compared with the test results.

• Journal of Korean Society of Steel Construction
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• v.22 no.6
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• pp.599-608
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• 2010

Steel trusses that act compositely with concrete slabs have proven to be an economical system for long-span floors. The composite action is generally achieved by providing shear connections between the steel top chord and the concrete topping. The composite sections have greater stiffness than the sum of the individual stiffnesses of the slab and truss. Therefore, steel trusses that act compositely with concrete slabs can carry larger loads and are stifferand less prone to transient vibration. During the tests that were performed in this study, the crack pattern and deflection of the beam of the composte truss were investigated. The test results were compared with the results for the noncomposite trusses.

• Journal of Korean Society of Steel Construction
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• v.14 no.6
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• pp.747-754
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• 2002

Cold-formed steel truss system was reviewed in order to improve the various problems associated with the steel floor joist system, such as the structural deficiency caused by web punching and others. Two types of floor truss system using cold-formed steel were reviewed during this research project, including the square end type(SE type) and underslung type(EE type). The strctural behavior was analyzed using the AISI design criteria and various bending tests. Test results show that the SE type floor truss proved to be more efficient than the EE type when it is subjected to concentrated load, and that the unbraced length of the floor truss about the weak axis has much importance on the buckling strength of the floor truss. Test results indicate that their values surpass the calculated values predicated through the AISI design criteria.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.4
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• pp.400-413
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• 2016

The horizontal shear capacity when the flange of a steel girder is replaced with 80 MPa concrete is important for its structural safety. In this study, 6 specimens with different interface conditions were designed and fabricated based on the Limit State Design Code on Korean Highway Bridges and static tests were performed to measure the horizontal shear capacity. Not only the resistance factors of the stud shear connector, concrete and reinforcement, but also the surface conditions of the casing concrete and spacing of the horizontal shear reinforcements were used as the experimental variables. The experiments showed that the interfaces between the steel girder and the concrete flange have stronger joint performance than those between the concrete flange and deck slab. To ensure the composite action in the plastic zone, the conservative horizontal shear reinforcement is more important than the roughness in the concrete face.

• Journal of the Society of Naval Architects of Korea
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• v.51 no.4
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• pp.300-310
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• 2014

This paper presents a mooring design procedure of a floating offshore wind turbine. The environment data of south offshore area of Jeju collected from Korea Hydrographic and Oceanographic Administration(KHOA) are used for hydrodynamic analyses as environmental conditions. We considered a semi-submersible type floating wind turbine based on Offshore Code Comparison Collaborative Continuation(OC4) DeepCWind platform and National Renewable Energy Laboratory(NREL) 5 MW class wind turbine. Catenary mooring with studless chain is chosen as the mooring system. Important design decisions such as how large the nomial sizes are, how long the mooring lines are, how far the anchor points are located, are demonstrated in detail. Considering ultimate limit state and fatigue limit state based on 100-year return period and 50-year design life, respectively, longterm predictions of breaking strength and fatigue are proposed.

• Journal of Korean Society of Steel Construction
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• v.26 no.5
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• pp.441-452
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• 2014

In this paper, steel reinforced concrete(SRC) column and composite beam connections were statically tested under gravity loading. The composite beam consists of H-section and U-section members. Five full-scaled specimens were designed to investigate the effect of a number of parameters on behavior of connections such as H-section size, the presence of stud connector, the presence of stiffeners and top bars. In addition, structural performance of welded joint between the H-section and the U-section members is mainly discussed, with an emphasis on initial stiffness, strength, deformation capacity.

• Journal of Korean Society of Steel Construction
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• v.20 no.4
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• pp.519-528
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• 2008

A simple steel-concrete composite deck is developed for preventing the lateral torsional buckling of girders that are under construction and for reducing the term of works using H-shaped rolled beams as bridge girders. A new type of shear connectors is also developed for the composite behavior between a simple steel-concrete composite deck and the rolled beams by the connecting conditions between the deck and the girders. One is a connector bolt that is lengthened and split or tightened with two nuts and the other is an I-shaped rolled beam welded on a steel plate with a number of holes punched through the web. In this study, to estimate the shear strength of those shear connectors the push-out tests are performed and the test results are compared with that of the previous studies and the codes. The result of the push-out tests of the connector bolts showed that the shear performance is similar to that of the stud connector and revealed that the equation for the shear strength in the Korean Specification of Highway Bridge overestimates the shear capacity of the connector bolt whose diameter is larger than 19mm. From the push-out tests of punched I-shaped rolled beams with varying welding amounts, with the small amount of welding, shear capacity is governed by the shear capacity of welding. On the other hand, shear capacity is governed by the size of the punched I-shaped rolled beams, regardless of the amount of welding.