• Proceedings of the Computational Structural Engineering Institute Conference
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• 2011.04a
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• pp.67-70
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• 2011

해안에 위치한 철근콘크리트 구조물 및 사회 간접 시설물들은 염해피해에 대한 우려가 있다. 염해피해로 인한 철근의 부식현상이 발생하면 철근과 콘크리트 부착성능의 저하로 인한 부재의 내력감소를 가져 올 수 있다. 따라서 본 연구에서는 염해부식이 진행되어 콘크리트와 철근간의 부착 및 비부착 여부에 따른 성능을 확인하기 위하여 완전 비부착된 보-기둥 접합부를 철근부착용 고무튜브를 이용하여 제작하였다. 제작된 실험체로 준정적 반복횡하중을 이용한 실험을 통해 성능평가를 수행하였다. 비부착된 보-기둥 접합부의 비선형 해석을 하기 위해 4절점 래티스 모델로 개선하여 적용하였다.

• Journal of the Korean Geotechnical Society
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• v.16 no.5
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• pp.157-168
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• 2000

토류구조물의 안정문제로는 장단기적으로 정적인 경우와 동적인 경우, 그리고 지반의 동적 거동특성, 흙의 강도저하 등을 미리 파악하여 기술적인 대처를 할 필요가 있을 것이다. 본 연구에서는 실내 모형 실험을 통하여 구조물의 배면에 토성이 다른 일반모래, 표준모래, 점성토를 뒷채움하여 다짐없이 강사만 하고, 룰러다짐, 진동다짐을 하여 토피의 수평 진동거리를 길게, 짧게 그리고 중간으로 하여 강성벽체에 작요？는 수평토압에 대한 정적, 동적 특성을 규명하는 것이다. 모형 실험장치로는 실험대, 토조, 토압측정장치, 진동하중 발생장치, 진동측정장치, 강사기, 롤러 등을 설치하여 거리에 따른 병진운동으로 가속도와 수평토압, 수평토압계수, 전체토압, 토압의 작용점, 지진토압증분 증을 구하여, 실험결과와 기존 이론결과, 그리고 유한요소 해석결과와 비교 고찰하였다.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.35 no.12
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• pp.1082-1088
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• 2007

Demand for high speed sea transportation modes has been increased dramatically last few decades. The WIG(Wing-in-ground effect) is considered as next generation maritime transportation system. In the structural design of high speed marine vessels, an estimation of water impact loads is essential. The dynamic structural responses of the WIG excited by the water impact loads may bring an important contribution to their damage process. The work presented in this paper is focused on the numerical simulation of the water impact on the WIG craft when it lands. It is aimed to study the structural responses of the WIG craft subjected to the water impact loads. The Arbitrary Lagrangian-Eulerian (ALE) finite element method is used to simulate the water impact of the WIG craft during a landing phase. A full 3D shell element is used to model the WIG craft in carbon composites, and a developed FE model is used to investigate the effect of the water impact loads on the structural responses of the WIG craft. In the analysis, two different landing scenarios are considered and their effects on the structural responses are investigated.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4A
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• pp.659-675
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• 2006

Recently, significant progress has been made in performance-based engineering methods that rely mainly on nonlinear static seismic analysis procedures. The Capacity Spectrum Method (CSM) and the Displacement Coefficient Method (DCM) are the representative nonlinear static seismic analysis procedures. In order to evaluate the applicability of the procedures to the seismic evaluation and design process of new and existing structures, the accuracy of both CSM and DCM should be evaluated in advance. The accuracy of seismic responses by the nonlinear static procedures is evaluated in comparison with the shaking table test results for the structural wall specimen subjected to the far field and near field earthquakes. Also conducted are comparative studies where the shaking table test results are compared with those from nonlinear dynamic analysis procedures, i.e., Single-Degree-of-Freedom (SDOF), equivalent SDOF and Multi-Degree-of-Freedom (MDOF) systems.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.173.2-173.2
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• 2012

위성체가 발사체에 실려 발사될 때에 매우 높은 가속도에 의한 정적, 동적 하중 및 공기의 저항에 의한 하중, 연소 가스 분출시 발생하는 음향에 의한 하중, 발사체로부터 분리될 때 발생하는 충격 하중 등 여러 가지의 극심한 하중을 겪게 된다. 이러한 발사 환경에 대한 안정성을 검토하기 위해 발사체 업체에서 제공하는 매뉴얼 상의 설계 조건을 이용하여 설계하고 해석하여 검증한다. 천리안 위성의 후속 위성으로 해상도 및 채널 성능 향상된 차세대 기상탑재체를 탑재하는 정지궤도 복합위성을 개발 중이다. 임무 수명 기간을 연장할 수 있는 3.5톤급 혹은 그 이상의 플랫폼에 대한 형상 설계를 수행하였고 그 내용을 목적으로 한다.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.113-116
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• 2008

According to a domestic provision, test levels of the barrier are divided into seven categories(SB1 to SB7) and the corresponding crash conditions are specified. Meanwhile, standard types of concrete barriers with different dimensions have been constructed nation wide. Some studies aimed at finding a proper test level of each type of the concrete barrier have been carried out, but the reliable and consistent results have not been fully established yet. The purpose of this study is to find out the test level corresponding to the concrete barrier of type-2 through static test. AASHTO LRFD was referred to for the loading pattern and a magnitude of the load that simulate a vehicle crash assumed. The test results show that the ultimate strength of the type-2 satisfies the load level required for SB5. However, it seems that the type-2 does not comply with SB6, showing some differences in results from previous analytical studies. In order to take advantage of the static test in establishing the test level of the domestic barrier, more detailed provisions should be specified.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.41 no.7
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• pp.561-568
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• 2013

After we designed Bearingless rotor hub system for 7,000lb class helicopter, flexbeam fatigue analysis was conducted for validation of requirement life time 8,000 hours. sectional structural analysis method applying elastic beam model was used. Fatigue analysis for two sections of flexbeam which were expected to weak to fatigue damage from result of static analysis was conducted. Extension, bending and torsion stiffness of flexbeam section shape was calculated using VABS for structure analysis. S-N curve of two composite material which composed flexbeam was generated using wohler equation. Load analysis of bearingless rotor system was conducted using CAMRAD II and load analysis result was applied HELIX/FELIX standard load spectrum to generate bearingless rotor system load spectrum which was used flexbeam fatigue safe life analysis.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.31 no.3D
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• pp.421-431
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• 2011

In this paper, actual bridges constructed with SMA (Stone Mastic Asphalt) deck pavement and virtual bridges substituted the deck pavement with polymer concrete under the same conditions were statically analyzed to investigate applicability of the thin polymer concrete bridge deck pavements. PSC (prestressed Concrete) girder bridge, steel box girder bridge, PSC box girder bridge, and RC (Reinforced Concrete) rahmen bridge constructed with the SMA deck pavement were analyzed and compared to evaluate various types of the bridge. The bridge deck and pavement were assumed to be fully bonded and the stress and deformation during the construction were ignored while those due to pavement weight and vehicle loading were analyzed. According to the analysis results, the stress and deformation of the bridges using the polymer concrete due to the pavement weight were smaller than those using the SMA because of smaller self weight due to lighter unit weight and thinner thickness of the pavement. The stress and deformation of the bridges using the polymer concrete due to the vehicle loading were larger than those using the SMA because of the smaller area moment of inertia due to the thinner pavement thickness. In case that the pavement weight and vehicle loading applied simultaneously, the stress and deformation of the bridges using the polymer concrete were smaller because effect of self weight reduction was more dominant. Investigation of performance of the bridge deck pavement and analysis of economical efficiency are warranted.

• Journal of Korean Society of Steel Construction
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• v.23 no.4
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• pp.455-464
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• 2011

In this study, the buckling analysis of the vertically curved stiffened web plate was conducted through finite-element analysis, using an eight- and nine-node flat shell element with a substitute shear strain field. To investigate the buckling behavior of the vertically curved web plate with a longitudinal or vertical stiffener under in-plane moment loading, parametric studies were conducted for the variation of the width (b) and ratio of the bending stiffness of the stiffener to that of the plate (${\gamma}=EI/bD$). The static behavior of the vertically curved web plate without a stiffener was also investigated, and then the buckling abilities of the longitudinal and vertical stiffeners were compared under moment loading.

• Journal of the Korea institute for structural maintenance and inspection
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• v.13 no.6 s.58
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• pp.183-191
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• 2009

In this study, the behavior and safety factor of a nailed-soil excavation wall during earthquake is presented. The horizontal displacement, axial force, shear force, and moment of facing of a nailed-soil excavation wall subjected to static and seismic load are analyzed using time history analysis. The safety factor based on the strength reduction technique proposed by Dawson and Roth is used to calculate the safety factor of a nailed-soil excavation wall during earthquake. The safety factor by the proposed method is verified by comparing with those by other methods.