• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1135-1137
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• 2005

단위 무게당 추력특성이 다른 전동기에 비해 우수한 것으로 나타나 있는 횡축형 선형전동기에 대한 연구가 많이 진행되고 있다. 본 논문에서는 횡축형 선형 전동기의 동적 시뮬레이션을 수행할 수 있는 시뮬레이션 모델을 개발하였다. 전동기의 설계단계에서는 주로 정적인 특성만을 고려하여 설계가 진행되지만, 이렇게 설계된 전동기는 실제 실험 결과와 설계 명세간의 차이가 많이 발생하는 경우가 있다. 본 논문에서 개발된 동적 시뮬레이션 모델을 이용한 결과를 설계 단계에서 적용한다면 좀 더 실제적인 전동기 설계를 할 수 있을것으로 기대된다. 또한 제작된 전동기의 성능 평가를 하는 경우 성능의 기준으로 활용할 수 있을 것으로 생각된다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.39 no.3
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• pp.311-318
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• 2015

A nonlinear dynamic response structural optimization process is proposed for the television (TV) packing system that protects the damage from a drop situation using the equivalent static loads (ESLs). Topology optimization using ESLs is carried out for conceptual design, and shape optimization using stress ESLs for a virtual model is performed for detailed design. Stress ESLs are static loads that generate the same displacement as well as the stress fields of linear static analysis as those of nonlinear dynamic analysis. Thus, the response of nonlinear dynamic analysis can be utilized as a constraint in the linear static structural optimization. An actual example is solved to validate the process. The drop test of a television packaging system is analyzed by LS-DYNA, and NASTRAN is used for optimization.

• Journal of the Earthquake Engineering Society of Korea
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• v.11 no.2 s.54
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• pp.95-104
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• 2007

Three types of high-rise RC building structures having irregularity in the lower two stories were selected as prototypes and were performed nonlinear static analysis by using OpenSees to verify the analysis technique and to investigate the seismic capacity of those buildings. The first one has a symmetrical moment resisting frame (Model 1), the second has an infilled shear wall in the central frame (Model 2), and the third has an infilled shear wall only in one of exterior frames (Model 3). Fiber model, which consists of concrete and reinforcing bar represented from stress-strain relationship, is adapted used for simulate the nonlinearity of members, and MVLEM(Multi vertical linear element model) is used for simulate the behavior of wall. The analytical results are simulate the behavior of piloti stories well, for example, the stiffness and yield farce of piloti stories, the up-lift of wall and the variation of lateral stiffness of column due to the variation of axial forces. Overstrength of Model 2 and Model 3 are about 2 times larger than that of Model 1. The reason of the high oversttrength and ductility of Model 2 and Model 3 is that the conservative design of Model 2 and Model 3, whose beam and column sections are the same as those of Model 1. The ductilities of Model 1 and Model 3 are slightly larger than that of Model 1 and Model 3. Model 1 and Model 3 reached mechanism condition, whereas Model 2 failed to the shear failure of shear wall and the large axial forces in columns due to large overturning moment.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1990.10a
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• pp.47-54
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• 1990

Under external loads, large panel structures behave quite differently from monolithic wall structures, because of the distinct planes of weakness in the horizontal and vertical joints between panels. Study on the ultimate load and the failure mode of the large panel structures under extream lateral loads is therefore important. The purpose of this study is to predict the nonlinear behavior of the structure using the general purpose nonlinear computer program 'ANSR' being based on the quasi-static test results of the large panel structure(full scale in two story) and to examine the distribution and change mode of the internal forces which can not be obtained in the test.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.18 no.3
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• pp.321-332
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• 2005

In this paper, the time-domain finite element formulations for axisymmetric linear viscoelastic problems, especially for the viscoelastic hollow sphere and cylinder, under various boundary conditions are presented with the theoretical solutions of them obtained by using the elastic-viscoelastic correspondence principle. It is assumed that the viscoelastic material behaves like a standard linear solid in distortion and elastically in dilatation. Numerical examples are solved based on the spherically symmetric, axisymmetric and plane strain finite element models. Good agreements are obtained between numerical and theoretical solutions, which shows the validity and accuracy of the presented method.

• Journal of the Korean GEO-environmental Society
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• v.24 no.9
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• pp.15-24
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• 2023

The behavior of buried pipes is directly influenced by the nonlinearity and complex characteristics of the surrounding soil. However, the simplified beam-spring model, which ignores the nonlinearity and complex behavior of soil, is commonly used in practice. In response, several studies have employed continuum analysis methods to account for the nonlinear and complex behavior of the soil. This paper presents various numerical continuum analysis techniques and verifies their comparison with full-scale tests. The study found that reaction force results close to the full-scale test could be obtained by applying contact surface characteristics that take into account the interaction between the ground and the buried pipe. In the case of sharing pipe and soil node method and ignoring the interaction between pipe and soil, excessive reaction force was derived, and the failure shapes were different. In addition, this study applied the dynamic explicit analysis method, ALE method, and CEL method. It was confirmed that the displacement-reaction relationship and failure shape are similar to those of the static analysis.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.2-5
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• 2010

최근 공동주택 거주자의 공간변화 욕구에 대응하기 위하여 가변성 평면이 가능한 구조시스템에 대한 연구가 활발히 진행되고 있다. 이에 따라 건식벽체 구조시스템, 복합 무량 벽체 구조시스템, 격간벽 시스템 등 구조적으로 안정성이 확보되면서 공간가변성이 뛰어난 구조시스템이 대안으로 제시되었다. 본 연구에서는 격간벽 시스템의 지진해석을 통해 내진성능을 평가하였다. 비선형 정적해석 및 동적해석 결과 격간벽 시스템은 벽식 구조시스템에 비하여 초과강도가 작고, 연성이 다소 감소하지만 FEMA-356에서 정하는 붕괴 방지 수준을 만족하여 충분한 내진성능을 보유한 것으로 나타났다.

• Proceedings of the Korea Concrete Institute Conference
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• 1992.10a
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• pp.196-201
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• 1992

The purpose of this study is to develop the computer software for the nonlinear analysis of R/C frame structure under static loads. For this purpose, strain-rate dependant material model and physical element model considering both flexural and shear deformation are adopted and they are connected with 'TWO-D'which is commerical software for elastic structural analysis. The analytical results using the developed software are compared to the experiment results and they are generally satisfactory.

• Transactions of the Korean Society of Mechanical Engineers
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• v.8 no.4
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• pp.385-393
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• 1984

본 연구에서는 다트식 낙하충격 시험에 있어서 인성의 강소성 플라스틱 재료 의 준정적 선형의 점탄성 모델이 구성되어 해석되었다. 완화계수함수, E(t)=E$_{f}$ +(E$_{o}$ -E$_{f}$ )e$^{-t/tR}$ 형태의 점탄성 재료의 수정된 Maxwell요소모델을 근거 로 충격속도, 파괴에너지, 임계응력등의 중요변수들의 상대적 종속성이 근사계산으로 평가되었다.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.289-292
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• 2010

본 연구에서는 기둥이 제거되는 경우 선형정적해석법을 사용하여 부재력을 산정하고 확률 신경망을 이용하여 그 분포를 파악하였다. 1층 내부기둥이 제거될 경우 다른 부재의 부재력이 가장 큰 것으로 나타났다. 확룰신경망을 이용하여 부재력의 분포를 파악하고 추정하는 것은 연쇄붕괴 시 초고층 건물이나 비정형 건물에 대한 위험부재를 선정하고 파악하는데 시간과 노력을 경감할 수 있는 것으로 나타났다.