• Steel and Composite Structures
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• 제21권2호
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• pp.343-356
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• 2016

As the common cast-in-place construction works fails to meet the enormous construction demand under rapid economic growth, the development of prefabricated structure instead becomes increasingly promising in China. For the prefabricated structure, its load carrying connection joint play a key role in maintaining the structural integrity. Therefore, a novel end plate bolt connecting joint between fully prefabricated pre-stressed concrete beam and high-strength reinforcement-confined concrete column was proposed. Under action of low cycle repeated horizontal loadings, comparative tests are conducted on 6 prefabricated pre-stressed intermediate joint specimens and 1 cast-in-place joint specimen to obtain the specimen failure modes, hysteresis curves, skeleton curves, ductility factor, stiffness degradation and energy dissipation capacity and other seismic indicators, and the seismic characteristics of the new-type prefabricated beam-column connecting joint are determined. The test results show that all the specimens for end plate bolt connecting joint between fully prefabricated pre-stressed concrete beam and high-strength reinforcement-confined concrete column have realized the design objectives of strong column weak beam. The hysteretic curves for specimens are good, indicating desirable ductility and energy dissipation capacity and seismic performances, and the research results provide theoretical basis and technical support for the promotion and application of prefabricated assembly frames in the earthquake zone.

• 한국농공학회지
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• 제17권4호
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• pp.3921-3930
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• 1975

This research was carried out to investigate several mechanical characteristics of pre-stressed steel beams. The configuration of specimens used for this study were as follows; a cover plate having permissible fiber stress of 4,000 kg/$\textrm{cm}^2$ was welded at bottom having the allowable bending stress 2500 kg/$\textrm{cm}^2$ steel beam, the section ratios of pre-stressed steel beam and cover plate were 0.5 and 0.6. Adopted pre-stresses were 0%, 50%, and 100% of an allowable fiber stress of a steel beam. The results obtained from the study may be summarized as follows; 1. The elastic range of a beam was increased by the application of pre-stress to the beam, which leads to a lighter section. 2. The permissible moment capacity of a pre-stressed steel beam was greated than that of a steel beam without pre-stressing. 3. The equivalent allowable stress induced by adopting the different section ratio of pre-stressed beam to cover plate were figured out 4. The optimum value of section ratio of beam and cover plate was 0.3 to 0.4 in case of a 1.5m span composite beam, a combination of an allowable stress 2,500kg/$\textrm{cm}^2$ steel beam and a permissible fiber stress 4,000 kg/$\textrm{cm}^2$ steel cover plate, was used. 5. The magnitude of the pre-stress was desirable to be same as the allowable stress of a steel beam. 6. It was concluded that if the construction techniques in the field are developed and improved, the practicing of pre-stress to the steel structure has a promising future.

• 대한기계학회논문집 C: 기술과 교육
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• 제3권2호
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• pp.97-106
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• 2015

Flexible structures are often important components of mechanical assemblies in motion. A flexible structure sometimes must go through assembly steps that cause it to be in a pre-stressed condition when in the starting position for operation. A virtual prototype of the assembly must also bring the model of the flexible structure into the same pre-stressed condition in order to obtain accurate simulation results. This case study is presented regarding the simulation of a constant velocity joint, with a focus on the flexible boot. The case study demonstrates that careful definition of the initial conditions of the boot and flexible body contacts yields high-fidelity simulation results.

• Computers and Concrete
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• 제17권2호
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• pp.201-214
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• 2016

The outer tank of a liquefied natural gas (LNG) storage tank is a longitudinally and meridianally pre-stressed concrete (PSC) wall structure. Because of the current trend of constructing larger LNG storage tanks, the pre-stressing forces required to increase wall strength must be significantly increased. Because of the increase in tank sizes and pre-stressing forces, an extreme loading scenario such as a bomb blast or an airplane crash needs to be investigated. Therefore, in this study, the blast resistance performance of LNG storage tanks was analyzed by conducting a blast simulation to investigate the safety of larger LNG storage tanks. Test data validation for a blast simulation of reinforced concrete panels was performed using a specific FEM code, LS-DYNA, prior to a full-scale blast simulation of the outer tank of a 270,000-kL LNG storage tank. Another objective of this study was to evaluate the safety and serviceability of an LNG storage tank with respect to varying amounts of explosive charge. The results of this study can be used as basic data for the design and safety evaluation of PSC LNG storage tanks.

• Wind and Structures
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• 제22권6호
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• pp.663-684
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• 2016

Conical vortices generated at the corner regions of large-span flat roofs have been investigated by using the Particle Image Velocimetry (PIV) technique. Mean and instantaneous vector fields for velocity, vorticity, and streamlines were measured at three visual planes and for two different flow angles of $15^{\circ}$. The results indicated that conical vortices occur when the wind is not perpendicular to the front edge. The location of the leading edge corresponding to the negative peak vorticity and maximum turbulent kinetic energy was found at the center of the conical vortex. The wind pressure reaches the maximum near the leading edge roof corner, and a triangle of severe suctions zone appears downstream. The mean pressure in uniform flow is greater than that under turbulent flow condition, while a significant increase in the fluctuating wind pressure occurs in turbulent streams. From its emergence to stability, the shape of the vortex cross-section is nearly elliptical, with increasing area. The angle that forms between the vortex axis and the leading edge is much smaller in turbulent streams. The detailed flow structures and characteristics obtained through FLUENT simulation are in agreement with the experimental results. The three dimensional (3-D) structure of the conical vortices is clearly observed from the comprehensive arrangement of several visual planes, and the inner link was established between the vortex evolution process, vortex core position and pressure distribution.

• 한국전산구조공학회논문집
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• 제27권4호
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• pp.313-320
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• 2014

텐세그리티 구조물은 인장력을 받는 연속된 케이블 안에 압축력을 받는 스트럿이 결합된 형태로 구성된다. 텐세그리티 구조물은 자기 응력 상태를 갖는 프리스트레스 핀 접합 구조물에 속한다. 텐세그리티 구조물 설계의 핵심은 평형 배열상태를 구하는 일명 형상탐색 과정이다. 본 논문에서는 세 가지의 효과적인 텐세그리티 구조물의 형상탐색 기법을 제안하였다. 형상탐색과정을 수행하면 평형상태의 내력 밀도와 그에 대응하는 위상을 얻을 수 있다. 이 때 평형상태를 형성하는 적절한 내력밀도 값을 얻기 위해 유전자 알고리즘을 결합한 내력밀도법이 사용되었다. 수치해석 예제를 통해 제안 알고리즘의 효율성을 입증하였다.

• Steel and Composite Structures
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• 제21권1호
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• pp.177-194
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• 2016

The cable-supported ribbed beam composite slab structure (CBS) is a new type of pre-stressed hybrid structure. The standard construction method of CBS including five steps and two key phases are proposed in this paper. The theoretical analysis and experimental research on a 1:5 scaled model were carried out. First, the tensioning construction method based on deformation control was applied to pre-stress the cables. The research results indicate that the actual tensile force applied to the cable is slightly larger than the theoretical value, and the error is about 6.8%. Subsequently, three support dismantling schemes are discussed. Scheme one indicates that each span of CBS has certain level of mechanical independence such that the construction of a span is not significantly affected by the adjacent spans. It is shown that dismantling from the middle to the ends is an optimal support dismantling method. The experimental research also indicates that by using this method, the CBS behaves identically with the numerical analysis results during the construction and service.

• Computers and Concrete
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• 제13권1호
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• pp.1-16
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• 2014

To evaluate the behavior of the advanced unbonded pre-stressed concrete containment vessel (UPCCV) for one typical China nuclear power plant under Japan's March 11 earthquake, five nonlinear time history analysis and a nonlinear static analysis of a 1:10 scale UPCCV structure have been carried out with MSC.MARC finite element program. Comparisons between the analytical and experimental results demonstrated that the developed finite element model can predict the earthquake behavior of the UPCCV with fair accuracy. The responses of the 1:10 scale UPCCV subjected to the 11 March 2011 Japan earthquakes recorded at the MYG003 station with the peak ground acceleration (PGA) of 781 gal and at the MYG013 station with the PGA of 982 gal were predicted by the dynamic analysis. Finally, a static analysis was performed to seek the ultimate load carrying capacity for the 1:10 scale UPCCV.

• 기술사
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• 제34권5호
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• pp.29-33
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• 2001

This paper summarizes the design and construction of the roof canopy structure for the SEOUL 2002 World Cup Main Stadium with a design inspired by Korean traditional beauty emphasizing images of the Pangpae kite. The stadium has also been designed for maximization of its post-World Cup utility to be used on as every basis by the citizens. The stadium canopy is a unique spatial network of truss members with a tensile membrane roof suspended from 16 masts. The canopy covers 40,950 ㎡. which is clad with a pre-stressed tensile membrane of PTFE coated fiberglass fabric and the glass.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2008년도 정기 학술대회
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• pp.511-516
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• 2008

Recently, many researchers are studying a high-strength concrete, composite materials and composite structures to build structures more economic and stable all over the world. For instance, there is CFTA(Concrete Filled and Tied Steel Tubular Arch) girder that applies an arch structure and a pre-stressed structure to CFT(Concrete Filled Steel Tubular) Structure to maximize the efficiency of structure and economic. In this study, linear-elastic behavior analysis of CFTA gider filled with high-strength concrete was performed by using ABAQUS 6.5-1 and also the result was analyzed.