• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.661-671
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• 2018

Domestic studies on steel plate concrete structures have focused on nuclear structures with high strength. In this study, the SC structure was applied to the general structure, and the SC structure that is advantageous in terms of safety and construction was limited to a special structure. As a basic study for applying SC, this paper proposes basic design information of a SC structure applying cement concrete to plan the structure, which is suitable for eco - friendliness by replacing concrete cement, an important factor in a SC structure, with blast furnace slag. This study examined the compression characteristics and the effective length factor under central compression load. To calculate the effective length factor, the Euler column theory was applied without applying plate theory. The effective length factor was calculated from the yield strength of the steel plate, buckling of the steel plate, and the point at which the concrete was broken. In addition, this study examined whether the maximum compressive strength meets the national and international reference equations with the slenderness ratio (B/t) as a parameter. By analyzing the buckling of the specimen by applying the column theory and selecting the strain of the measured steel plate, the effective length factor was analyzed and compared with the value presented in the reference equation.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.146-150
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• 2011

본 연구에서는 길이 35.6m, 폭 4m, 사행도 1.8의 2회 사행하는 복단면 사행하도의 상류 직선부와 만곡 정점부 6개 지점에 폭 0.4m, 길이 0.8m의 타원기둥 형태의 부유 구조물을 구성하여, 0.25m, 0.40m의 수심 조건으로 수치모의를 수행하였다. 수치모의 결과자료 중에서 부유 구조물 주변의 흐름특성을 국부적으로 분석해 본 결과 부유 구조물이 없을 때의 흐름과는 상당히 다른 흐름특성들이 발견되었는데, 특히 그 중에서도 부유 구조물 아래에서 작용하는 상승류와 부유 구조물로 인한 단면 이차류의 분리가 두드러졌다. 이와 함께 수로 유입부와 유출부 사이의 총 수두 값 변화도 수로 내 부유 구조물의 유무에 따라 다르게 나타났다. 그리고 이러한 결과들 모두 동일 측선 상에서라도 부유 구조물의 위치가 바뀌면 다른 양상으로 나타났다. 본 연구에서는 하도 내에 부유 구조물이 있을 때 부유 구조물의 위치에 따른 통수능 및 흐름특성의 변화를 3차원 수치모의 결과를 통하여 보여준다. 그리고 그 결과들은 하도 내 부유 구조물을 설치 할 때, 검토대상에 부유 구조물 뿐 아니라 하도형태 및 하천의 흐름특성도 함께 포함되어야 함을 뒷받침해준다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.2
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• pp.51-58
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• 2022

Flat plate slab is cost-efficient structural system widely used in high rise building, apartment and parking garages. But flat plate-column connections are so weak against punching shear failure that it may cause collapse of overall structure. In this study, spiral type shear reinforcement which increases the shear strength and ductility of the plate-column connection and has good workability was proposed. And experimental test was performed to verify the punching shear capacity of spiral type shear reinforcement. The current code does not accurately estimate the punching shear strength of slab-column connection with shear reinforcement because slab is so slender that punching failure may occurred before shear reinforcement reached yield stress. Therefore modified equation of ACI code for punching shear strength was proposed base on finite element analysis using LUSAS program, and data analysis from CEB-FIP database.

• Journal of Korean Society of Steel Construction
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• v.17 no.4 s.77
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• pp.419-429
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• 2005

The objective of this study is to clarify the structural features of members consisting of a connection, as part of the previous study on the CFT column-to-beam tensile connection with a combined cross diaphragm. This connection has the following merits: it evenly distributes the stress on the beam flange and the diaphragm and reduces the stress concentration by improving the stress transfer route and restraining the abrupt deformation of the diaphragm. Finite element analysis was performed to find out the stress transfer through the sleeve, which is an important member of the connection with a combined cross diaphragm. The length and thickness of the sleeve were used as variables for the analysis. The analysis results showed that the length and thickness of the sleeve did not influence the capacity of the connection and played the role of a medium for the transfer of the stress from the diaphragm to the filled concrete. It was proposed that the appropriate length of the sleeve have the same value as the diameter of the sleeve and that the appropriate ratio of the sleeve diameter to the sleeve thickness be 20. Two equations for the evaluation of the load carrying the capacity of the connection were also proposed through the modification of the evaluation equation suggested in the previous study.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1993.10a
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• pp.24-31
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• 1993

In the design of column, computation of effective length factor for calculation of allowable compressive stress is inevitable. In this study. computer code which automatically generates effective length factor in the finite element analysis is developed. The program is developed to be used for orthogonal and nonorthogonal frame structure. Some i1lustrative examples verify that the computation results we correct for various cases.

• Proceedings of the KAIS Fall Conference
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• 2011.12b
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• pp.511-513
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• 2011

인구증가와 지속적인 산업발전으로 인하여 에너지 소비가 급증하게 되면서 효율적인 에너지 사용의 필요성이 크게 대두되었다. 특히 건물의 창문을 통해 많을 에너지 손실이 일어나 이를 해결하고자 현재 로우이(low-emissivity)유리를 사용하고 있으나 이는 태양광의 유입을 줄이는 단순한 방법으로 여전히 상대적으로 높은 열관류율을 갖고 있다. 이를 해결하고자 현재 단열성능이 좋은 고효율 진공유리가 개발 중이나 아직 가격 및 성능 등의 문제로 본격적인 보급은 이루어지지 않고 있다. 본 논문에서는 내부압력, 지지기둥(spacer)의 길이 및 지름 등이 진공유리 성능에 미치는 영향을 3차원 수치해석을 통하여 알아보았다.

• Journal of the Korean Institute of Gas
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• v.17 no.1
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• pp.13-18
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• 2013

Experimental studies were carried out to investigate the interactions between the propagating flame fronts and different multiple obstacles within an explosion chamber. The explosion chamber is 600 mm in height, $700{\times}700mm^2$ in cross-section and has a H/L value of 0.86. Three different multiple obstacles with the blockage ratio of 0.43 were replaced within the chamber. The results showed that relatively higher local flame displacement speed was observed with the triangular obstacle while the lower was observed with the circular one. It was found that the local flame displacement speeds behind the obstacle were largely dependent on the obstacle types. It was also found that as the flame interacted with the flow field generated behind the obstacle, the probability density functions(PDFs) of the local flame displacement speed were extensively distributed toward higher speeds.

• Journal of Korean Tunnelling and Underground Space Association
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• v.9 no.4
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• pp.351-359
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• 2007

Multi-axial compression tests have been frequently conducted to evaluate the in situ properties of rock masses and the mechanical behaviors of rock strata through the model tests. Without the proper boundary condition for the model tests, the mechanical behavior of rock mass would deviate, as can be expected, from the in situ conditions. The boundary condition will affect the internal stress distribution of the specimens and cause some distortion on the measurement. In this study, a design process regarding the steel brush, which has been employed for multi-axial compression test to reduce the frictional restraint along the specimen/loading platen interface, is introduced. The individual brushes are regarded as a simple column and beam to calculate the cross-sectional size and length of the brushes in consideration of the buckling capacity and the allowable deflection.

• Journal of Korean Society of Steel Construction
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• v.27 no.5
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• pp.435-445
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• 2015

Concrete filled steel tube(CFT), which has superior ductility and strength, is used for building column, bridge piers of ocean structure. Shear design equations of CFT existing in structural design provisions are excessively conservative. It has an effect on constructability and the economics of CFT. However, to suggest the reasonable shear design equation, experimental studies on the shear capacity of CFT have been rarely conducted. This study is analytical research to suggest improved shear design equations of large-diameter concrete-filled steel tubes. This analytical research was conducted to apply finite element analysis model of CFT based on the prior research. It was verified by comparison with prior test results. The verified model was used for parameter studies to estimate the influence of overhang length, concrete compressive strength and diameter-thickness ratio on shear strength.

• Journal of Korean Society of Steel Construction
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• v.15 no.6 s.67
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• pp.701-709
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• 2003

The paper presented the seismic performance of T-stiffener moment connections for use in steel moment-resisting frames. The connections were strengthened by welding the vertical and horizontal clement of the T-stiffener to the beam flange and column f1ange. Finite clement analysis and experiments were conducted to determine the behavior of T-stiffener-reinforced connections. The results of the finite element analysis confirmed the effectiveness of the T-stiffener, whose horizontal element lengthened to mitigate local stress concentrations of the beam flange on the horizontal stiffener. Full-scale specimens were also tested cyclically to study hysteresis behavior. The main parameters used were the ratio of the T-stiffener to beam strength and the shape of the horizontal element. As the length of the horizontal element increased, the deformation capacity of the connections enhanced. Likewise, all specimens behaved according to the Ramberg-Osgood curve and showed stable hysteresis behavior.