• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 B
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• pp.690-692
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• 2000

In this paper voltage distribution in the windings of an inverter fed induction motor is studied. High frequency parameters of the induction motor are calculated using finite element analysis. With these parameters. a high frequency equivalent circuit of the inverter-cable-motor is formed. The transient analysis is performed using ATP-EMTP package to estimate the voltage distribution in the motor windings.

• Geomechanics and Engineering
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• 제5권4호
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• pp.299-312
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• 2013

The horizontal pullout capacity of a group of two vertical strip plate anchors, placed along the same vertical plane, in a fully cohesive soil has been computed by using the lower bound finite element limit analysis. The effect of spacing between the plate anchors on the magnitude of total group failure load ($P_{uT}$) has been evaluated. An increase of soil cohesion with depth has also been incorporated in the analysis. For a weightless medium, the total pullout resistance of the group becomes maximum corresponding to a certain optimum spacing between the anchor plates which has been found to vary generally between 0.5B and B; where B is the width of the anchor plate. As compared to a single plate anchor, the increase in the pullout resistance for a group of two anchors becomes greater at a higher embedment ratio. The effect of soil unit weight has also been analyzed. It is noted that the interference effect on the pullout resistance increases further with an increase in the unit weight of soil mass.

• 교육시설
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• 제14권4호
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• pp.25-33
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• 2007

The purpose of this study is to develop the category, intelligent element technologies and detail items for application of intelligent school. The result of this study will be a basic data to improve the intelligent school. For this purpose, analyze domestic and foreign intelligent system and through interview, survey with professional group, developed item was evaluated and for verifying and reappraising the items the researcher visited and interviewed teachers of three elementary schools. Developed intelligent items were composed of twelve basic technologies and fifty-four detail technologies.

• 전산구조공학
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• 제6권3호
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• pp.99-112
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• 1993

유한요소생성기법중 삼각요소를 생성하는 들로네이-보로노이 기법은 반복되는 국지적 요소재편을 통하여 요소망을 완성하는 기법으로 적응유한요소법의 적용에 이점이 되고 있다. 이 방법의 요체는 재편대상이 되는 요소군의 형성과 이를 대체하는 요소생산의 과정이다. 이를 간편하게 해결하는 방법으로 요소의 인접성을 나타내는 행렬을 새로이 도입하고 이에 따르는 단순 알고리즘을 제시하여 일반 PC급 이용자들도 본 요소생성기법을 이용한 적응유한요소해석의 실질적인 적용가능성을 제고하였다.

• Structural Engineering and Mechanics
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• 제53권3호
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• pp.429-442
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• 2015

The measurement from the indentation process depends on the amount of pile-up or sink-in around the contact impressions. In this paper, finite element concept is utilized to study the pile-up and sink-in behaviour for the wide range of materials with different young's modulus, yield stresses, strain-hardening exponents and coefficient of friction values. The exact indentation model is created by using the two dimensional axisymmetrical model for simulating the spherical indentation process on the lines of Taljat and Pharr (2004) work. The result shows that during spherical indentation process the amount of pile-up is greatly influenced by the strain hardening exponents in addition to other material properties and depth of penetration. The numerical results from the finite element analysis are also validated using the exact multilinear material properties obtained from the tensile testing for the materials like mild steel, brass and aluminium.

• Structural Monitoring and Maintenance
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• 제3권2호
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• pp.129-144
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• 2016

We present a methodology to validate with monitoring data finite element models of existing concrete dams: numerical analyses are performed to assess the structural response under the effects of seasonal loading conditions, represented by hydrostatic pressure on the upstream-downstream dam surfaces and thermal variations as recorded by a thermometers network. We show that the stiffness effect of the rock foundation and the surface degradation of concrete due to aging are crucial aspects to be accounted for a correct interpretation of the real behavior. This work summarizes some general procedures developed by this research group at Politecnico di Milano on traditional static monitoring systems and two significant case studies: a buttress gravity and an arch-gravity dam.

• Architectural research
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• 제20권1호
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• pp.9-16
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• 2018

Nonlinear analysis of reinforced concrete (RC) structures is performed by using isogeometric Reissner-Mindlin (RM) shell element. The elasto-plastic constitutive model is employed to express the nonlinear behavior of concrete material and the equivalent smeared steel layer is introduced to represent steel reinforcement. The arc-length control method is used to produce the entire load-displacement path of RC structures. Finally, three benchmark tests are carried out to verify the performance of the present shell element. From isogeometric analysis, the present results show a good agreement with experimental results and it is provided as future benchmark test solutions.

• Journal of Mechanical Science and Technology
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• 제20권5호
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• pp.621-633
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• 2006

To reflect the size effect of material $(1\sim15{\mu}m)$ during plastic deformation of polycrystalline copper, a constitutive equation which includes the strain gradient plasticity theory and intrinsic material length model is coupled with the finite element analysis and applied to plane strain deformation problem. The method of least square has been used to calculate the strain gradient at each element during deformation and the effect of distributed force on the strain gradient is investigated as well. It shows when material size is less than the intrinsic material length $(1.54{\mu}m)$, its deformation behavior is quite different compared with that computed from the conventional plasticity. The generation of strain gradient is greatly suppressed, but it appears again as the material size increases. Results also reveal that the strain gradient leads to deformation hardening. The distributed force plays a role to amplify the strain gradient distribution.

• Smart Structures and Systems
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• 제9권5호
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• pp.411-426
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• 2012

Thin-walled adaptive structures render a large and important group of adaptive structures. Typical material system used for them is a composite laminate that includes piezoelectric material based sensors and actuators. The piezoelectric active elements are in the form of thin patches bonded onto or embedded into the structure. Among different types of patches, the paper considers those polarized in the thickness direction. The finite element method (FEM) imposed itself as an essential technical support for the needs of structural design. This paper gives a brief description of a developed shell type finite element for active/adaptive thin-walled structures and the element is, furthermore, used as a tool to consider the aspect of mesh distortion over the surface of actuators and sensors. The aspect is of significance for simulation of behavior of adaptive structures and implementation of control algorithms.

• 한국전기전자재료학회논문지
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• 제13권3호
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• pp.265-272
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• 2000

In this paper the corona discharge in SF$_{6}$ gas used as insulating material in lots o high voltage equipment, is simulated by finite element method with Flux-Corrected Transport(FCT) method. By application of proposed method the negative corona discharge characteristics in needle to plane electrode is analyzed with time step. For the accuracy of analysis the secondary electron emission by photon and ion are also considered as well as the accuracy of analysis the secondary electron emission by photon and ion are also considered as well as townsend first ionization and electron attachment. The calculated results show that the electric field intensity between anode and ion group is decreased as times go-by according to field distortion by those space charge. Accordingly the electron density is decreased strongly by the attatchment effect of SF6 gas so that the corona discharge becomes extinguished abruptly.y.