• 한국항해학회지
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• 제22권3호
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• pp.65-72
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• 1998

최근에는 고장력강의 사용증대와 함께 구조부재가 경량화추세에 있으며 이상부식이 발생한 구조부재는 강도가 크게 저하되리라 예상되지만 지금까지 이에 관한 연구가 거의 없는 상태이다. 본 연구에서는 단소성대변형유한요소법을 적용하여 국부이상부식을 가진 판이 면내압축하중을 받을 경우에 압축최종강도에 미치는 부식부영역의 크기. 부식부의 판두께 감소량 및 세장비의 영향에 대하여 연구하였다.

• Structural Engineering and Mechanics
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• 제37권3호
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• pp.321-330
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• 2011

Long-term properties of concrete affect structures in many respects, not excepting dynamic behaviors. This paper investigates the influence of concrete creep on the dynamic behaviors of concrete filled steel tube (CFT) arch bridges, by means of combining the analytical method for the creep of axially compressed CFT members, which is based on Model B3 for concrete creep, with the finite element model of CFT arch bridges. By this approach, the changes of the stress and strain of each element in the bridge with time can be obtained and then transformed into damping and stiffness matrices in the dynamic equation involved in the finite element model at different times. A numerical example of a long-span half-through CFT arch bridge shows that creep influences the natural vibration characteristics and seismic responses of the bridge considerably, especially in the early age. In addition, parameter analysis demonstrates that concrete composition, compressive strength and steel ratio have an obvious effect on the seismic response of the CFT arch bridge.

• 한국철도학회논문집
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• 제6권4호
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• pp.273-278
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• 2003

In this study, an aluminum bodyshell with a modular front end made of composite materials is numerically evaluated applying the standard specifications for the urban EMU (Electric Multiple Unit) train. Structural analyses under compressive load, torsional load and free vibration satisfy the standard specifications, but analysis under normal load doesn't. By the way, the aluminum bodyshell of the car except the modular front end is almost same to that of the Korean standard EMU, which satisfy the standard specifications. It is presumed that the stiffness of the modular front end made of composite materials has some influence on the strength of the aluminum bodyshell.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2002년도 가을 학술발표회 논문집
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• pp.557-564
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• 2002

One of the primary factors like plate structure In ship is redundancy structure that is comparable with ocean structure and frame structure. The more component material becomes buckling collapsed locally the less structure stiffness becomes accordingly. As a result, by increasing the load distribution of any other subsidiary structure continually component member collapses, therefore the structure could be in danger of collapse. So, in order to interpret this phenomenon precisely, the study on boundary condition of the ship's Plate and post-buckling analysis must be considered. In this study, the rectangular plate is compressed by the in-plane load. Buckling ＆ Ultimate strength characteristics we applied to be the elasto-plasticity large deformation by F.E.M. On this basis, elasto-plasticity of the plain plate are investigated. This study proved elasto-plasticity behaviour of tile ship's plate In accordance with boundary condition based on the series analysis In case of the compressive load operation.

• 한국철도학회:학술대회논문집
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• 한국철도학회 1998년도 창립기념 춘계학술대회 논문집
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• pp.466-473
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• 1998

LRV(Light Rail Vehicle) is one of the most useful way for urban transit. HDPIC has designed and manufactured the LRV train set for Manila Line 1 expansion. The LRV is composed of two carbody sections which are coupled by a articulated bogie. The articulated bogie and two motorized bogies have slewing rings in order to improve the curving performance and ride quality. Carbody structures are mainly made of low-carbon stainless steel (STS301L), and the carbody bolsters and draft sills are made of rolled steel for welded structures. The authority's specifications specified the design load conditions and weight limits. Design load conditions are vertical load, compressive load and diagonal jacking, and the maximum axle load is 10.7 ton. In order to meet those requirements, the stiffness and strength of carbody structure were predicted using finite element analysis during design stage. The half or full structure is modeled and analyzed with design load conditions, and critical areas are analysed in detail using sub-modeling method. The strength and strength of carbody structure was also verified by the load test. The analysis and test results show a good agreement.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2003년도 가을 학술발표회 논문집
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• pp.591-598
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• 2003

The purpose of this study is to investigate the seismic behavior of reinforced concrete Containment Panel subjected to earthquake motions. A computer program, named RCAHEST(Reinforced Concrete Analysis in Higher Evaluation System Technology), was used for the analysis of reinforced concrete structures. A 4-node flat shell element with drilling rotational stiffness is used for spatial discretization. The layered approach is used to discretize behavior of concrete and reinforcement through the thickness. Material nonlinearity is taken into account by comprising tensile, compressive and shear models of cracked concrete and a model of reinforcing steel. The smeared crack approach is incorporated. Solution of the equations of motion is obtained by numerical integration using Hither-Hughes-Taylor(HHT) algorithm. The proposed numerical method for the seismic analysis of reinforced concrete Containment panel is verified by comparison of analysis results with reliable experimental results.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 춘계학술발표대회 논문집
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• pp.47-50
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• 2004

Weight reduction of the carbody is of great concern in developing high speed tilting train. Currently the composite materials are widely applied to the carbody structure due to their excellent material properties such as high specific strength and stiffness characteristics. In this paper, finite element analysis was conducted to design sandwich structures of composite carbody of the Korean Tilting Train eXpress(TTX). Several load tests on the carbody according to JIS E 7105, such as static vertical, compressive and torsional load tests was performed by finite element analysis, and the structural safety of composite carbody structure was verified.

• Coupled systems mechanics
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• 제9권3호
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• pp.281-287
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• 2020

Nanotechnology is an upcoming technology that can provide solution for combating pollution by controlling shape and size of materials at the nanoscale. This review provides comprehensive information regarding the role of nanotechnology in pollution control at concrete structures. Titanium dioxide (TiO2) nanoparticles are a good item for concrete structures for diminishing the air polluting affect by gasses of exhaust. In this article, the mixture rule is presented for the effect of nanoparticles in environmental pollution reduction in concrete structures. The compressive strength, elastic modulus and reduction of steel bars in the concrete structures are studied. The Results show that TiO2 nanoparticles have significant effect on the reduction of environmental pollution and increase of stiffness in the concrete structures. In addition, the nanoparticles can reduce the use of steel bars in the concrete structure.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2005년도 춘계학술대회 논문집
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• pp.458-461
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• 2005

In this paper, a new type of inchworm motion actuator is developed in fabrication of actuators for micro-press machine. This is consisted of three piezoelectric actuators, one is for moving the tool guide and the other are for clamping the guide. The inchworm motor provides both high load and large displacement in small size actuator. PZT has compressive strength and often fails under tensile stress and pulling. Thus, in order to prevent failure, we have designed pre-load housing and accomplished FEM analysis. The pre-load housing was used for determining the optimal design condition by comparing the von-mises stresses with the change of hinge stiffness. Also, in order to predict the performance of the motor under certain conditions, the system model was simulated using MATLAB. This is open loop control actuator and driven by the period of input voltage.

• Earthquakes and Structures
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• 제2권1호
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• pp.1-24
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• 2011

During very strong earthquakes, seismically isolated buildings may experience large horizontal relative displacements, which may lead to poundings if an insufficiently wide clearance is provided around the building. This paper investigates, through numerical simulations, the effectiveness of using rubber bumpers, which could be attached at locations where it is likely to have impacts, in order to act as shock-absorbers. For the simulation of the dynamic behavior of such rubber bumpers during impacts, a nonlinear force-based impact model, which takes into account the finite thickness of the rubber bumpers, has been developed. Subsequently, a series of parametric analyses are performed to assess the effect of the gap size, the earthquake characteristics and the thickness, compressive capacity and damping of the bumpers. The stiffness of the moat wall is also parametrically considered during poundings of a seismically isolated building, as another potential mitigation measure for poundings of seismically isolated buildings.