• 전산구조공학
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• 제2권3호
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• pp.85-95
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• 1989

본 논문에서는 Rayleigh파, 전단파 및 압축파의 영향을 동시에 해석할 수 있는 주파수 종속 무한요소와 이를 이용한 지반-구조물의 동적상호작용의 해석법에 대하여 연구하였다. 방사적으로 전파되는 응력파의 성분에 대한 무한요소와 아울러 매립(Embedded)기초나 적층(Layered)지반을 해석하기 위하여 수평으로 전파되는 파를 해석할 수 있는 무한요소를 개발하였고, 요소행렬 구성하기 위한 적분시 하나의 파성분만 존재하는 경우에 대하여 효율적으로 적용되었던 Newton Cotes 적분과 유사한 방법을 Multi-Waves 문제에 알맞게 확장 적용하였다. 이 방법의 타당성은 반무한, 균질 지만의 위에 놓여있는 원형강판과 지반에 묻혀 있는 원통형 강체기초의 Compliance 함수를 구하여 기존의 문헌에 발표된 값과 비교함으로써 검증하였다. 예제해석은 지진하중을 받는 원자력발전소 격납구조를 대상으로 하여 수행하였으며, 매립깊이의 크기, 지반의 재료감쇠 및 지반의 모형기법에 따른 구조물-지반의 상호작용의 해석결과를 비교 분석하였다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.419-424
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• 2004

we performed the underwater explosion analysis for the liquefied oxygen tank - a kind of fuel tank of a mid-size submarine, and tried to verify the structural safety for this structure. First, we reviewed the theory and application of underwater explosion analysis using Structure-Fluid Interaction technique and its finite element modeling scheme. Next, we modeled the explosive and sea water as fluid elements, the LOX tank as structural elements and the interface between two regions as ALE scheme. The effect on shock pressure and impulse of fluid mesh size and shape are also investigated. As the analysis result, the shock pressure due explosion propagated into the water region and hit the structure region. The plastic deformation and the equivalent stress highly appeared at the web frame and the shock mount of LOX structure, but these values were acceptable for design criteria.

• Structural Engineering and Mechanics
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• 제45권4호
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• pp.439-454
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• 2013

Hollow cylindrical tubes with a prismatic sandwich lining designed to replace the solid cross-sections are studied in this paper. The sections are divided by a number of revolving periodic unit cells and three topologies of unit cells (Square, Triangle and Kagome) are proposed. Some types of multiple-topology designed materials are also studied. The feasibility and accuracy of a homogenization method for obtaining the equivalent parameters are investigated. As the curved elements of a unit cell are represented by straight elements in the method and the ratios of the lengths of the curved elements to the lengths of the straight elements vary with the changing number of unit cells, some errors may be introduced. The frequencies of the first five modes and responses of the complete and equivalent models under an internal static pressure and an internal step pressure are compared for investigating the scope of applications of the method. The lower bounds and upper bounds of the number of Square, Triangular and Kagome cells in the sections are obtained. It is shown that treating the multiple-topology designed materials as a separate-layer structure is more accurate than treating the structure as a whole.

• 대한전자공학회논문지
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• 제19권6호
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• pp.9-16
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• 1982

이 설계 과정은 보통의 더지탈 하아드웨어 담계에 복합 기계 개념을 응용한 일설계 기법을 소개한 것이다. 이 과정은 계산기용 소프트웨어 설계의 경우와 마찬가지로 새 시스템을 흐름도에 의해 표현시키는 것으로 부터 시작되며, 이어서 흐름도를 분해하여 발산형 요소를 얻고, 이 발산형 요소를 근거로 소기계를 작성하게 되는데, 이렇게 소기계의 작성이 끝나게 되면. 이번에는 통합 과정을 통해서 복합체와 지시기를 만들고, 논리자로를 완척함으로써 전휴의 설계 과정을 완료하게 된다. This is an introduction to an art of digital hardware design using polymachine image as a target structure of the product. As in the case of software design of a computer, the design process begins with a sketch of planned system in flow chart description and the flow charts is partitioned into divergent elements. Each of the element machine is derived from those divergent elements. We can build a complete digital system with the preparation of an index, and a polymer of these element machines.

• International Journal of Concrete Structures and Materials
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• 제1권1호
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• pp.29-36
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• 2007

The purpose of this paper is the assessment of the capacity of the reinforced concrete (RC) elements of an arch bridge when they are subjected to contact and near-contact explosive charges of various amounts, and the estimation of the critical charges for these components. The bridge considered is the Tenza Viaduct, a decommissioned structure south of Naples, Italy. Its primary elements, deck, piers and arches were analyzed. The evaluation was accomplished via numerical analyses that made possible to obtain the elements dynamic response when they are exposed to blast loading conditions. To evaluate the member's capacities, failure criteria for deck, piers and arches were proposed based on concrete damage parameters. Additionally, curves relating the explosive charge to the residual capacity and to damage level of the elements were also developed. The results of this work were taken into account to investigate the progressive collapse of the global structure.

• 한국의류산업학회지
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• 제21권5호
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• pp.527-539
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• 2019

This study examined the Chinese style in the Vivienne Tam collection as well as explored diversity and modern interpretation of a Chinese style used in modern fashion. The study also investigated the concept and history of the Chinese style as well as analyzed the Chinese style in the collection based on a consideration of a Chinese element that is the basic structure with an understanding of Vivienne Tam and general collection themes. As a result of research, the Chinese style appeared in the Vivienne Tam collection was comprehensive with 43 Chinese elements including Animals, Flower & Grass among the Nature elements, Mythology Religion among the Figure elements, Historical Artifacts, Clothing, Oral Literature, Entertainment, Fine Arts. Technique, Folk holiday among Culture elements and Philosophy among Spirit elements, which accounted for 57.6% of the collection. The formative characteristics that included Chinese elements were extended, abstracted, distorted or transformed; in addition, some abstract elements were embodied into animals, images and certain particular forms to present a theme. In addition to two-dimensional method to print Chinese elements on fabric, they were also expressed as a three-dimensional texture or a silhouette, achieving clear and bold harmony. The aesthetic characteristic is a mixture of Eastern and Western way of thinking. Her costume has a political and historical meaning beyond the imitation of elements that represent the development of a pleasant and interesting design.

• 한국정밀공학회지
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• 제27권1호
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• pp.49-57
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• 2010

This paper describes the design, construction, and fundamental testing of a precision rotational device that utilizes piezoelectric elements as a source of driving force and impact drive mechanism as a driving principle. A novel device structure is designed and the numerical simulations about the static displacement, stress distribution, and mode shape of the designed structure are performed. A fabricated rotational device has been rotated successfully by applying saw-shaped voltages to the piezoelectric elements. The one-step rotational angle was $0.44{\times}10^{-3}$ rad at the applied voltages of 80V. The angular velocities of the device were revealed to be increased as the driving frequency and voltage were respectively increased and the preload was decreased. The device has a feature that it can be translated as well as rotated. An experimental result shows that the device was translated by ${\pm}4.56{\mu}m$ maximum when the 120V sinusoidal voltages with a phase difference of $180^{\circ}$ were respectively supplied to two piezoelectric elements.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.200-207
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• 2006

A new formal standardization methodology of the structural design document information is proposed in this paper. The standardization process is divided into three steps: pre-process of the collected sample document (CSD), construction of the document structure, and definition of the occurrence of each element in the document. During the pre-process, the detail document contents in the CSD are indexed with templates defined in this study, and the indexed CSD is translated into XML Schema (XSD) formal Afterwards the degree of confidences of all elements between the temporary standard document (TSD) and the translated CSD are calculated by using the XML schema matching algorithm; the TSD is then updated. This second step is repeated until all of the CSD are compared. In the final step, the common elements and unbounded elements are extracted by determining the occurrence of the temporary document elements, and the standardized document schema is exported in the XSD format. The case study dealing with the structural calculation documents show that the ,proposed methodology can be effectively used to build a XML -based information model of structural design documents.

• Advances in aircraft and spacecraft science
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• 제9권5호
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• pp.377-400
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• 2022

The aim of this work is a numerical comparison (FEM) between lattice pyramidal-core panel and honeycomb core panel for different core thicknesses. By evaluating the mid-span deflection, the shear rigidity and the shear modulus for both core types and different core thicknesses, it is possible to define which core type has got the best mechanical behaviour for each thickness and the evolution of that behaviour as far as the thickness increases. Since a specific base geometry has been used for the lattice pyramidal core, the comparison gives us the opportunity to investigate the unit cell strut angle giving the higher mechanical properties. The presented work considers a detailed FEM modelling of a standard 3-point bending test (ASTM C393/C393M Standard Practice). Detailed FEM modelling addresses to detailed discretization of cores by means of beam elements for lattice core and shell elements for honeycomb core. Facings, instead, have been modelled by using shell elements for both sandwich panels. On lattice core structure, elements of core and facings are directly connected, to better simulate the additive manufacturing process. Otherwise, an MPC-based constraint between facings and core has been used for honeycomb core structure. Both sandwich panels are entirely built of Aluminium alloy. Prior to compare the two models, the FEM sandwich panel model with lattice pyramidal core needs to be validated with 3-point bending test experimental results, in order to ensure a good reliability of the FEM approach and of the comparison. Furthermore, the analytical validation has been performed according to Allen's theory. The FEM analysis is linear static with an increasing midspan load ranging from 50N up to 500N.

• 한국해양공학회지
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• 제24권2호
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• pp.34-40
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• 2010

When a large ship is advancing in waves, it undergoes hydroelastic response, which affects the structural stability and the fatigue destruction of the ship. Therefore, to predict an accurate hydroelastic response, it is necessary to conduct a thorough analysis of hydroelastic response, including fluid-structure interactions. In this research, the ship is divided into many hull elements, to calculate the fluid forces and wave exciting forces on each element. Using the three-dimensional source distribution method, the calculated fluid forces and wave exciting forces are assigned to nodes of the hull elements. The neighbor nodes are connected with elastic beam elements. We analyzed hydroelastic responses, using the finite elements method.