• Journal of the Computational Structural Engineering Institute of Korea
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• v.28 no.1
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• pp.19-27
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• 2015

Recently, the most of domestic high-rise residential complex buildings are constructed with reinforced concrete structures, which may bring structural problems during construction. This study is aimed to analyze structural safety and lateral load-resisting performance of RC high-rise residential complex building under construction. The tower-typed building with 60 floors is selected as a sample model, and numerical analyses are performed. The structural performances of building structures at construction stages, which are resulted form the analyses of numerical models completed up to 10th, 20th, 30th, 40th, 50th, or 60th floor, are compared to those of the completed building structure. For the comparisons of structural performances, modal shapes and fundamental periods of building structures, lateral load-resisting performances, and structural design performances of structural members are considered. The lateral displacement and story drift ratio are analyzed for lateral load-resisting performances, and comparisons of design ratios at construction and design stages are performed for structural design performances of structural members. The guideline of design loads and structural analysis schemes for checking the safety of RC high-rise building under construction is presented.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.12
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• pp.37-42
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• 2007

Clock grid networks are now common in most high performance microprocessors. This paper presents a new effective modeling and simulation methodology for the clock grid using scattering parameter. It also shows the effect of wire width and grid size on the clock skew of the grid. The interconnection of the clock grid is modeled by RC passive elements. The results show that the error is within 10 % comparing to Hspice simulation results.

• Magazine of the Korea Concrete Institute
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• v.16 no.4 s.81
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• pp.70-77
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• 2004

콘크리트 구조물에 대한 많은 기준들의 요건에 따르면, 휨을 받는 철큰 콘크리트(RC) 보의 압축부에서의 응력은 일반적으로 일축의 응력-변형을 관계를 이용하여 계산한다. 이와 같은 접근은 가끔씩 압축력을 받는 콘크리트에서 부서짐이 발성할 때 보의 구조적 거동을 재현하지 못할 수 있다. 결과적으로, RC 구조물의 지지력과 그들의 연성은 근사적으로 평가된다. 본 논문에서는 압축을 받고 있는 콘크리트의 postpeak 거동은 활동면을 이용하여 모델링되었다. 이 활동 면의 모멘트-곡률곡선에서 연화부분에 그 원인이 있다. 제안된 활동현상의 수학적 표현은 압축력을 받는 콘크리트(즉, 연화부분의 거동이 압축영역의 크기와 변형률구배(곡배)에 의존하는)에 있어서 특정한 응력-변형률 관계를 정의하는 것이 얼마나 어려운지를 보여주고 있다.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.731-736
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• 2002

The degradation of reinforced concrete (RC) structures due to physical and chemical attacks has been a major issue in construction engineering. Deterioration of RC structures due to chloride attack followed by reinforcement corrosion is one of the serious problems. The objective of this study is to develop a form of mathematical model of chloride ingress into concrete. In order to overcome some limits of the previous approaches, a mathematical model of chloride ingress into concrete consisting of chloride solution intrusion through the capillary pore and chloride ion diffusion through the pore water was proposed. Moreover, the variability of diffusivity of chloride ion due to degree of hydration of concrete, relative humidity in pore, exposure condition, and variation of chloride binding was considered in the chloride ingress model.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.229-233
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• 2003

This paper describes a practical formulation of Non-Bernoulli-Compatibility Truss Model. Not only equilibrium conditions but also some approximations are employed to solve for the unknowns included in the proposed model. By assuming that the ratio of $V_a$ to V remains to be constant along the shear span, the relationship between $\alpha$ and z is mathematically established as an arch shape function. $V_m$ is also approximated to be an empirical value that is equal to the least membrane shear strength. The coefficient a is made utilizing a nonlinear finite element analysis. The adequacy of the model is examined by test results available in literatures, and the predicted values are shown to be in excellent agreement with the experimental results.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.397-402
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• 2003

This paper presents strut-and-tie models for predicting shear strength of RC interior beam-column joints considering the plastic hinge rotation of adjacent beams. On seismic design of frame system, it is controlled beams to occur plastic hinges and to be ductile so as to dissipate earthquake energy efficiently. The plastic hinge deformation of beams is used as analysis parameter in terms of strain of beam tensile bars at column face. The shear strengths of beam-column joints are evaluated by combining direct strut mechanism with truss mechanism. It is assumed that the max force transferred by direct strut mechanism is based on the strength of cracked concrete element, and that by truss mechanism is based on bond capacity.

• Magazine of the Korea Concrete Institute
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• v.9 no.1
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• pp.195-206
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• 1997

비선형 layered 유한요소법과 비선형 프로그래밍 기법에 의하여 주어진 기존의 철근콘크리트 보의 휨강도 및 연성을 근사하게 나타낼 수 있는 강섬유고강 철근콘크리트 보(Reinforced Steel Fibrous Concrete Beam : RSFC Beam)의 인장 및 압축철근량, 강섬유의 혼입률 등을 산정하였다. 개발된 모델을 이용하여 콘트리트의 압축강도 및 철근비가 서로 다른 일반 철근콘크리트 보에 있어서 강섬유보강 콘크리트를 사용할 경우, 기존 철근을대체하는 강섬유의 량과 또한 이로 인한 인장 \ulcorner 압축 철근량의 변화량을 조사하였다. 기존 문헌에 나타난 강섬유보강 콘크리트보의 전간강도식을 이용하여 일반 철근콘크리트보와 비교하여 강섬유보강 철근콘크리트 보에서 증가될 수 있는 스터럽의 간격을 산정하였다.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.367-370
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• 2005

This study is to propose a truss model which is able to reasonably predict the shear strength of reinforced concrete (RC) members with high-strength materials. The shear strengths of 107 RC test beams with high-strength steel bars reported in the technical literatures were compared to those obtained from proposed model, TATM, and existing truss models. The shear strength of reinforced concrete beams obtained from test was better predicted by TATM than other truss models. Also, the theoretical results by TATM were almost constant regardless of yield strengths and steel ratios of tension and shear reinforcements.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.413-416
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• 2004

This paper describes a proposal for crack width and deflection in RC flexural members. Because the serviceability provisions of the current codes are mainly based on only empirical relationships developed from test result and effective moment of inertia, crack width and deflections are contrary to the actual values. Based on nonlinear bond characteristics, tension stiffening effect, arch action and effective concrete tensile area. Then an equation is developed for predicting crack width and deflection in flexural members. The predicted results shows that as proposed model employed, crack width and deflections are different from estimated by the current KCI, MC 90 and EC 2 provisons, and the values predicted are in good agreement with experimentally measured values.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.265-268
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• 2006

Recently, many design standards recommend the use of a strut-tie model approach for design of structural concrete with D-region(s). However, since the design standards of the conventional strut-tie model approaches are suggested on the assumption of using a determinate strut-tie model, it is difficult to apply an indeterminate strut-tie model in the design of continuous deep beams. In this study, an indeterminate strut-tie model for continuous deep beams is proposed to resolve the problem, and the ultimate strengths of 35 continuous deep beams tested to failure are evaluated for the validity check of the proposed indeterminate strut-tie model. The analytical results by the proposed model are compared with those by the conventional approaches of ACI 318-99 and ACI 318-05.