• 대한기계학회논문집
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• 제17권11호
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• pp.2704-2710
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• 1993

A simple and straightforward method is introduced for developing continuum beam-rod model of a box-beam typed aircraft wing with composite layered skin based on "energy equivalence." The equivalent continuum structral properties are obtained from the direct comparison of the reduced stiffness and mass matrices for box-beam typed wing with those for continuum beam-rod model. The stiffness and mass matrices are all represented in terms of the continuum degrees-of freedom defined in this paper. The finite-element method. The advantage of the present continuum method is to give every continuum structural properties including all possible coupling terms which represent the couplings between different deformations. To evaluate the continuum method developed in this paper, free vibration analyses for both continuum beam-rod and box-beam are conducted. Numerical tests show that the present continuum method gives very reliable structural and dynamic properties compared to the results by the conventional finite-element analysis. analysis.

• 대한기계학회논문집
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• 제19권3호
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• pp.615-622
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• 1995

It may be inefficient to conduct the aeroelastic analysis by using full-scale conventional finite-element analyses or experiments, from the initial design phase, for an aircraft wing which can be considered as the discontinuum complex structure with composite laminated skins. In this paper, therefore more efficient aeroelastic analysis has been conducted for a box-beam typed aircraft wing by using the equivalent continuum beam-rod model which is derived from the concept of energy equivalence. Equivalent structural properties of the continuum beam-rod model are obtained from the direct comparison of the finite-element matrices of continuum beam-rod model with those of box-beam typed aircraft wing. Numerical results by the continuum beam-rod model approach are compared with those by the conventional finite-element analysis approach to show that the continuum beam-rod model proposed herein is quite satisfactory as a simplified model of aircraft wing structure for aeroelastic analyses.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 봄 학술발표회 논문집
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• pp.197-204
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• 2002

In this study, multivariate analysis based on domestic data(958 EA) of road tunnel, and suggest the easy prediction equation of Q-system. We generate applicable Q-value to numerical analysis method with using the equation and investigate the behavior as variable Q-value of rock mass induced excavation with discontinuum numerical analysis method, UDEC. In the result of the experiment, we research the application range of Q-value to apply the continuum model to discontinuous rock mass is below 0.7 and we testify the applicability of continuum model as researched Q-value with continuum numerical analysis method, FLAC.

• 한국철도학회논문집
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• 제3권2호
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• pp.43-50
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• 2000

The corrugated panels are the prime candidate structure for the floor, roof and wall of Korean high speed train. The equivalent continuum modeling approach panels can be used for the efficient design and evaluation of their structural characteristics. The equivalent continuum models, derived from the true complex corrugated panels, should have the same structural behavior as the original structures have. This paper briefly reviews three representative continuum modeling methods: the static analysis method and two plate-models based on modal analysis methods (MAM). These methods are evaluated through some numerical examples by comparing the natural frequencies and static deflections. It is observed that the plate-model based on Rayleigh-Ritz method seems to provide the best results when used in conjunction with the cantilever-type boundary conditions. The equivalent elastic constants of various corrugated panels, depending on the changes in their configurations, are tabulated for efficient use in structural design.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.395-402
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• 2006

In analyzing the nano-scale phenomena or behaviors of nano devices or materials, it is often desirable to deal with more atoms than can be treated only with a full atomistic simulation. However, even now, it is advisable to apply the atomistic simulation to the narrow region where the deformation field changes rapidly but to apply the conventional continuum model to the region far from that region. This equivalent continuum model can be formulated by applying the Cauchy-Born rule to the exact atomistic potential as in the quasicontinuum method. To couple the atomistic model with the equivalent continuum model, continuum displacements are conformed to the molecular displacements at the discrete positions of the atoms within the bridging domain. To satisfy the coupling constraints, we apply the Lagrange multiplier method. The continuum model in the bridging model should be applied on the region where the deformation field changes gradually. Then we can make the nodal spacing in the continuum model be much larger than the atomic spacing. In the first step, we generate the atomic-resolution mesh with the nodal spacing equal to the atomic spacing, and then we eliminate the nodal degrees of freedom adaptively using the node deactivation techniques. We eliminate more DOFs as the regions are more far from the atomistic region. Computing time and computational resources can be greatly reduced by the present node deactivation technique in multi scale analysis.

• 대한기계학회논문집
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• 제16권6호
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• pp.1021-1029
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• 1992

본 연구에서는 거대한 평판형 격자구조물에 대한 등가 연속체모델을 유도하기 위한 보다 간편하고 합리적인 방법을 개발하고, 예제해석을 통해 새로이 개발된 방법 의 타당성을 보이는데 있다.

• 한국기록관리학회지
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• 제22권3호
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• pp.21-36
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• 2022

최근 기록이 지닌 정보로서의 속성에 주목해야 한다는 논의가 활발히 제기되고 있다. 이는 전자기록 환경을 맞아 행위에 대한 증거로서의 속성에만 초점을 맞추어 온 동향에 대한 반향이다. 하지만 아직까지 기록이 지닌 정보로서의 속성에 대한 명확한 개념은 정립되지 않은 상태이다. 이에 본고에서는 기록과 정보 간의 관계 정립을 위한 일환으로 정보 컨티뉴엄 모델을 분석하고자 한다. 정보 컨티뉴엄은 레코드 컨티뉴엄을 기반으로 레코드키핑 관점에서의 새로운 정보 개념을 정립하기 위해 고안된 이론 체계로, 레코드키핑 내에 존재하는 정보관리를 위한 요소들을 파악할 수 있는 하나의 개념적 틀을 제공해준다. 이에 2장에서는 레코드 컨티뉴엄 개발 이후 정보 컨티뉴엄이 개발된 배경 및 과정을 살펴본 다음, 구조주의 이론 등 정보학 이론을 차용해 정립한 정보의 개념을 레코드 컨티뉴엄과 연계하여 고찰하였다. 이어 3장에서는 정보 컨티뉴엄의 개념적 구조와 함께 정보의 활용 목적 및 방식을 고찰한 후, 레코드키핑 내에 존재하는 정보관리를 위한 요소들을 구조적으로 도식화한 정보 컨티뉴엄 모델상의 4개 차원 및 속성을 분석하였다. 이러한 분석을 기반으로 4장에서는 정보 컨티뉴엄이 지닌 의의 및 한계를 제시하고자 하였다.

• Steel and Composite Structures
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• 제21권3호
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• pp.501-515
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• 2016

Seismic analysis for steel frame structure with brace configuration using topology optimization based on truss-like material model is studied. The initial design domain for topology optimization is determined according to original steel frame structure and filled with truss-like members. Hence the initial truss-like continuum is established. The densities and orientation of truss-like members at any point are taken as design variables in finite element analysis. The topology optimization problem of least-weight truss-like continuum with stress constraints is solved. The orientations and densities of members in truss-like continuum are optimized and updated by fully-stressed criterion in every iteration. The optimized truss-like continuum is founded after finite element analysis is finished. The optimal bracing system is established based on optimized truss-like continuum without numerical instability. Seismic performance for steel frame structures is derived using dynamic time-history analysis. A numerical example shows the advantage for frame structures with brace configuration using topology optimization in seismic performance.

• Journal of Advanced Marine Engineering and Technology
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• 제32권6호
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• pp.931-937
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• 2008

The rail/wheel rolling contact affects the microstructure in the surface layer of rail. Recently. continuum damage mechanics allows us to describe the microprocesses involved during the straining of materials and structures at the macroscale. Elastic and plastic strains. the corresponding hardening effects are generally accepted to be represented by global continuum variables. The purpose of continuum damage mechanics is to introduce the possibility of describing the coupling effects between damage processes and the stress-strain behavior of materials. In this study. the continuum damage mechanics caused by elastic deformation was briefly introduced and applied to the fatigue damage of the rails under the condition of cyclic loading. The material parameter for damage analysis was first determined so that it could reproduce the life span under the compressive loading in the vicinity of fatigue limit. Some numerical studies have been conducted to show the validity of the present computational mechanics analysis.

• 한국기록관리학회지
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• 제21권3호
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• pp.1-16
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• 2021

레코드 컨티뉴엄은 전자기록 환경으로 이행하는 패러다임 전환기에 기록학의 기반을 제공하는 이론임에도 불구하고, 이에 대한 비판적 분석을 그동안 거의 수행되지 않았다. 레코드 컨티뉴엄은 아직 개발이 진행 중인 이론으로, 핵심은 라이프사이클 모델과는 다른 기록에 대한 새로운 시각이다. 따라서 전자기록 환경에서 레코드 컨티뉴엄이 지닌 의미 및 한계를 분석하고 보다 심도 있는 이론적 개발을 위해서는 레코드 컨티뉴엄 논리 속에 함유된 기록의 의미 및 속성에 대한 분석이 필수적으로 요구된다. 하지만 레코드 컨티뉴엄에서는 기록에 대해 별도로 정의를 내리지 않고 있다. 이에 본고에서는 최근의 전자기록 환경에서 레코드 컨티뉴엄 이론 속에 함유된 기록의 의미 및 속성을 축선 및 차원 분석을 통해 고찰하고자 하였다. 이를 위해 우선 기록의 의미 및 속성 도출을 위한 기초 작업으로, 컨티뉴엄 모델상의 차원 1 및 차원 2에 초점을 맞추어 분석을 수행하였다. 이어 컨티뉴엄 논리 속에 함유된 기록의 의미 및 속성을 라이프사이클 모델과 결부시켜 고찰하였으며, 이를 기반으로 컨티뉴엄이 지닌 의의를 고찰한 다음, 기록의 의미 및 속성 관점에서 컨티뉴엄이 지닌 한계를 제시하였다.