• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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• pp.418-421
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• 2006

Appropriate analysis models for concrete-filled steel tube (CFT) subjected to bending moment were determined to assess flexural behavior of CFT member. Applying this model, finite element analyses was performed and compared against experimental data considering the compressive strength of in-filling material and the composite action between tube shell and in-filling core. Analysis results showed that the FE model proposed in this study is feasible for the analytical investigation of the flexural behavior of CFT member according to loading conditions, effect of compressive strength of various core materials and other design parameters.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2002년도 추계학술발표대회 논문집
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• pp.198-201
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• 2002

It has been well-blown that sandwich structures are efficient to resist bending loads by increasing the moment of inertia of the panel. However, the accurate theoretical prediction of failure load and its optimization of sandwich beams for strength under concentrated loads were so complicated. Moreover, the appropriate selection of the variables, such as face thickness, core density and core thickness of the sandwich beam with many theories has continuously researched to satisfy for the given strength to weight structural requirement. There will be interesting to investigate the effect of those variables with its optimization for the load resistance.

• Steel and Composite Structures
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• 제35권4호
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• pp.495-508
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• 2020

Double skin composite walls are alternatives to concrete walls to resist gravity load in structures. The composite action between steel faceplates and concrete core largely depends on the internal mechanical connectors. This paper investigates the structural behavior of novel composite wall system with T section and under combined compressive force and bending moment. The truss connectors are used to bond the steel faceplates to concrete core. Four short specimens were designed and tested under eccentric compression. The influences of the thickness of steel faceplates, the truss spacing, and the thickness of web wall were discussed based on the test results. The N-M interaction curves by AISC 360, Eurocode 4, and CECS 159 were compared with the test data. It was found that AISC 360 provided the most reasonable predictions.

• 대한간호학회지
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• 제43권3호
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• pp.409-419
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• 2013

Purpose: The purpose of this study was to describe and explore the experience process of life of patients with Crohn's disease. Methods: Using a grounded theory methodology, 24 interviews were performed with 7 men and 5 women, 17-47 years of age, suffering from Crohn's disease. Results: 'Tuning of two conflicting lives' was identified as the core category, and 5 subcategories were identified and they were integrated into the core category. The identified outcomes were 'Living a withdrawn life', 'coping flexibly', 'drifting with tangled emotions' and 'maintaining long-term remission'. Conclusion: When caring for these patients, it is important to identify needs, allow patients to express what they want at that moment and support them in maintaining a daily life that can be perceived as normal.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2001년도 가을 학술발표회 논문집
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• pp.277-284
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• 2001

Recently, with development of mechanics of materials, as pursuing the high speed of the ships, a demanding of composite construction which satisfies high strength and low weight at the same time is iner casing. A sandwich element is a type of composite construction, which is composed of thin, strong, stiff and relatively high density faces and a think, light, and weaker core material. As 2nd moment is increased by faces is separated from the neutral axis farther, a sandwich element is most effective light structural form. In this paper, the make a comparative study Aluminum Honeycomb Sandwich Panel(AHSP) and Aluminum Pyramid Sandwich Panel(APSP).

• 한국농공학회지
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• 제31권2호
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• pp.125-134
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• 1989

This study was conducted to investigate the flexural behaviour of sandwich constructions with cement concrete core and polymer concrete facings. Six different cross-sectional shapes using epoxy based polymer concrete facings were investigated. Some of the results from the static tests are given including the load-deflection responses, load-strain relationships, ultimate moment, and mode of failure. From the. results the following conclusions can be made. 1. The various strengths of polymer concrete were very high compared to the strengths for portland cement concrete, while modulus of elasticity assumed an aspect of contrast. 2. The thickness of core and facing exerted a great influence on the deflection and ultimate strenght of polymer concrete sandwich constructions. 3. The variation shape of deflection and strain depend on loading were a very close approximation to the straight line. The ultimate strain of polymer concrete at the end of tensile side were ranged from 625x10-6 to 766x10-6 and these values increased in proportion to the decrease of thickness of core and facings. 4. The ultimate moments of polymer sandwich constructions were 3 to 4 times that of cement concrete constructions which was transformed same section. It should he noted that polymer concrete have an effect on the reinforcement of weak constructions. 5. Further tests are neede to investigate the shear strain of constructions, and thermal expansion, shrinkage and creep of cement and polymer concrete which were composite materials of sandwich constructions.

• 소음진동
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• 제6권6호
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• pp.827-834
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• 1996

본연구에서는 핵연료집합체의 검증계획의 일환으로 2차측 배관파단의 영향을 조사하였다. 원자로노심의 상세모델을 이용한 동적해석으로 배관파단에 의한 응답을 구하였다. 파단적 누설개념의 적용으로 10인치 이상의 고에너지 배관에 대하여 양단 파단이 설계에서 배제됨에 따라 본 연구에서는 주증기관과 급수관의 파단을 가정 하였다. 핵연료 집합체의 전단력, 굽힘모우멘트, 변위 및 지지격자체의 충격하중에 대하여 자세히 고찰하였고 이들 동적해석 결과를 이용하여 핵연료집합체의 구조적 건전성을 평가하였으며 사고조건에서 2차측 배관파단이 핵연료집합체의 구조적 건전성 에 미치는 영향을 검토하였다.

• Steel and Composite Structures
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• 제16권3호
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• pp.325-337
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• 2014

The strength and buckling problem of a five layer sandwich beam under axial compression or bending is presented. Two faces of the beam are thin aluminium sheets and the core is made of aluminium foam. Between the faces and the core there are two thin binding glue layers. In the paper a mathematical model of the field of displacements, which includes a share effect and a bending moment, is presented. The system of partial differential equations of equilibrium for the five layer sandwich beam is derived on the basis of the principle of stationary total potential energy. The equations are analytically solved and the critical load is obtained. For comparison reasons a finite element model of the beam is formulated. For the case of bended beam the static analysis has been performed to obtain the stress distribution across the height of the beam. For the axially compressed beam the buckling analysis was carried out to determine the buckling load and buckling shape. Moreover, experimental investigations are carried out for two beams. The comparison of the results obtained in the analytical and numerical (FEM) analysis is shown in graphs and figures. The main aim of the paper is to present an analytical model of the five layer beam and to compare the results of the theoretical, numerical and experimental analyses.

• 전기학회논문지
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• 제58권11호
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• pp.2128-2135
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• 2009

In this paper, current limiter using a magnetic switching which is based on magnetic flux change in the case of fault is proposed. This current limiter consists of iron-core and three parts of coils. One is the primary coil connected to the power system. Another is the secondary coil wound to the opposite direction of the primary coil's winding. The other is the secondary of the secondary coil which is a movable copper plate winding and located below the secondary coil. In the normal state, the magnetic flux produced in the primary and secondary coils flows to the opposite directions each other and becomes to be canceled out. Therefore the voltages induced between the coils are zero. In the case of a fault, at the moment of a fault occurrence recognition, the switch connected to a secondary coil is opened and the secondary of the secondary coil is pulled out to the outside of the iron-core. Then, magnetic flux becomes to flow through the iron-core. Accordingly, the voltage is induced between the both ends of the primary coil and makes the current reduced. Therefore it is possible to cut off the circuit breaker easily with the proposed current limiter. This paper analyzes the current limiting effects and the detailed results are given.

• 천문학회보
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• 제44권1호
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• pp.70.3-70.3
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• 2019

Understanding how the filamentary structure affects the formation of the prestellar cores and stars is a key issue to challenge. We use the Heterodyne Array Receiver Program (HARP) of the James Clerk Maxwell Telescope (JCMT) to obtain molecular line mapping data for two prestellar cores in different environment, L1544 in filamentary cloud and L694-2 in a small cloud isolated. Observing lines are $^{13}CO$ and $C^{18}O$ (3-2) line to find possible flow motions along the filament, $^{12}CO$ (3-2) to search for any radial accretion (or infalling motions) toward the cores of gas material from their surrounding regions, and $HCO^+$ (4-3) lines to find at which density and which region in the core gases start to be in gravitational collapse. In the 1st moment maps of $^{13}CO$ and $C^{18}O$, velocity gradient patterns implying the flow of material were found at the cores and its surrounding filamentary clouds. The infall asymmetry patterns of HCO+ and $^{13}CO$ line profiles were detected to be good enough to analyze the infalling motions toward the cores. We will report further analysis results on core formation in the filamentary cloud at this meeting.