• Title/Summary/Keyword: Light Weight Material

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A Comparative Study of the Houses of Mies van der Rohe and Le Corbusier (미이스 반 데르 로에 주택과 르 꼬르뷔제 주택의 비교 연구)

  • 김용립
    • Korean Institute of Interior Design Journal
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    • v.13 no.5
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    • pp.21-31
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    • 2004
  • There are probably no architects of the 20th Century who had more influence on modern architecture than Mies van der Rohe and Le Corbusier. Although the two architects share one thing in common, namely, both are master of modernism, each has developed unique architecture of his own. The objective of this study is to investigate the characteristics of their works through a comparison analysis of the Ideas, design principles and architectural language reflected in the works, focusing on the houses. this study will also aim to provide a foundation for a new design that harmonizes the design principles and architectural language of the two. Through the study the following common points and differences were found between the houses of the two. A) Common points: Both architects avoided ornamentation In houses while placing weight on the functions of houses and they tried to plan rational floor plans by separating the wall from the structure. B) Differences: \circled1 The houses of Mies express the structure in a straight forward manner, while those of Corbusier are formative houses focusing more on shapes. \circled2 The shapes of the houses of Mies are limited to basic shapes, quadrangle while those of Corbusier employ various geometric curves. \circled3 Using steel and glass, the houses of Mies are light and transparent. On the contrary, using concrete, the houses of Corbusier are somewhat bulky with Three-dimensional changes. \circled4 The houses of Mies show the value of moderation based upon the classical principles of design, while the houses of Corbusier show the value of moderation based upon geometry. \circled5 The houses of Mies feature horizontal intoners with flexibility. However, Corbusier's houses have vertical interiors with some changes in the cross sections. \circled6 In terms of material, the interiors of Mies' houses employ materials with various tones and textures, while interiors of Corbusier's houses are painted in simple white. Summing up these characteristics, it could be said that the houses of Mies have logical and rational beauty, whereas the houses of Corbusier have more emotional beauty.

STUDY ON A EFFECTIVE THERMAL CONDUCTIVITY OF THE CFRP COMPOSITE STRUCTURE BY A SIMPLIFIED MODEL (모델 단순화에 의한 CFRP 복합 구조물의 유효 열전도율 추출 방법 연구)

  • Kim, D.G.;Han, K.I.;Choi, J.H.;Lee, J.J.;Kim, T.K.
    • Journal of computational fluids engineering
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    • v.20 no.4
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    • pp.63-69
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    • 2015
  • The thermal balance test in vacuum chamber for satellite structures is an essential step in the process of satellite development. However, it is technically and economically difficult to fully replicate the space environment by using the vacuum chamber. To overcome these limitations, the thermal analysis through a computer simulation technique has been conducted. The CFRP composite material has attracted attention as satellite structures since it has advantages of excellent mechanical properties and light weight. However, the nonuniform nature of the thermal conductivity of the CFRP structure should be noted at the step of thermal analysis of the satellite. Two different approaches are studied for the thermal analyses; a detailed numerical modeling and a simplified model expressed by an effective thermal conductivity. In this paper, the effective thermal conductivities of the CFRP composite structures are extracted from the detailed numerical results to provide a practical thermal design data for the satellite fabricated with the CFRP composite structure. Calculation results of the surface temperature and the thermal conductivities along x, y, z directions show fairly good agreements between the detailed modeling and the simplified model for all the cases studied here.

Draft Proposal of Smart Outdoor Wear upon the Outdoor Wear Functionality Demand (아웃도어 웨어 기능성 요구에 따른 스마트 아웃도어 재킷 설계시안)

  • Paek, Kyung Ja;Lee, Jeong Ran
    • Fashion & Textile Research Journal
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    • v.16 no.3
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    • pp.446-455
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    • 2014
  • This study revealed the results related to the functionality of outdoor wear required when man and women in their 30s to 50s engage in outdoor activities. Based on the results of the survey, we proposed composition draft for a smart outdoor jacket with main functions of GPS device and light-emitting device using solar cell and EL. Absorption and release of sweat, functionality regarding rain and wind, and lightweightness, etc. from material functionalities of outdoor wear were found to be important. From function required in clothing for outdoor activity, location tracking, night glow, and lighting functions were found to be most important. For results investigating the necessity of the jacket's location tracking function and lighting function using solar cell, high scores of 3.9~4.0 were given. Purchase intentions for smart outdoor jacket with location tracking and lighting functions devised by this study were fairly positive and most responses indicated that the appropriate purchase price was between 200,000 to 300,000 won while possible problems of this smart outdoor jacket were listed in the order of washing inconvenience, high price, device weight, and discomfort in movement. The draft proposal to integrate with wearable devices for smart outdoor jacket prototype is as follows: Solar cell has been attached to the upper arm but placed inside a transparent pocket which has been detachable for washing convenience while the solar cell and controller have been integrated into a single unit. Using frequent movement exhibited by the arms, EL has been attached along the center line of the raglan sleeve for easy spotting when used as an emergency signal or for night lighting function during outdoor activity. GPS has been attached on the left sleeve so that the person can bend the left arm inward and operate the GPS screen with the right hand while walking or running outdoors.

Development of Element Technique for the Floating PV Generation Structure Using FRP (FRP를 활용한 수상 부유식 태양광발전 구조물의 요소기술 개발)

  • Seo, Su-Hong;Choi, Jin-Woo;Joo, Hyung-Joong;Nam, Jeong-Hun;Yoon, Soon-Jong
    • Composites Research
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    • v.27 no.3
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    • pp.103-108
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    • 2014
  • Fiber reinforced polymer plastic (FRP) structural members are recently available in construction industries due to various material properties such as high specific strength and stiffness, light-weight, and corrosionresistance. The floating PV generation structure can also be an illustration for applying FRP in construction applications. The floating PV generation structure has been recently issued as a representative item for the low carbon and green growth campaign and many related studies have been conducted for the structural safety and commercial viability. Moreover, the floating PV generation structures for the commercial purpose have been constructed. In this paper, the investigation and development processes of elements for the floating PV generation structure are presented during commercialization.

Design Analysis/Manufacturing /Performance Evaluation of Curved Unsymmetrical Piezoelectric Composite Actuator LIPCA (곡면형 비대칭 압전복합재료 작동기 LIPCA의 설계해석/제작/성능평가)

  • Gu, Nam-Seo;Sin, Seok-Jun;Park, Hun-Cheol;Yun, Gwang-Jun
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.10
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    • pp.1514-1519
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    • 2001
  • This paper is concerned with design, manufacturing and performance test of LIPCA ( Lightweight Piezo- composite Curved Actuator) using a top carbon fiber composite layer with near -zero CTE(coefficient of thermal expansion), a middle PZT ceramic wafer and a bottom glass/epoxy layer with high CTE. The main point of this design is to replace the heavy metal layers of THUNDER by thigh tweight fiber reinforced plastic layers without losing capabilities to generate high force and large displacement. It is possible to save weight up to about 30% if we replace the metallic backing material by the light fiber composite layer. We can also have design flexibility by selecting the fiber direction and the size of prepreg layers. In addition to the lightweight advantage and design flexibility, the proposed device can be manufactured without adhesive layers when we use epoxy resin prepreg system. Glass/epoxy prepregs, a ceramic wafer with electrode surfaces, and a graphite/epoxy prepreg were simply stacked and cured at an elevated temperature (177 $^{circ}C$ after following an autoclave bagging process. It was found that the manufactured composite laminate device had a sufficient curvature after detached from a flat mold. The analysis method of the cure curvature of LIPCA using the classical lamination theory is presented. The predicted curvatures are fairly in agreement with the experimental ones. In order to investigate the merits of LIPCA, a performance test of both LIPCA and THUNDE$^{TM}$ were conducted under the same boundary conditions. From the experimental actuation tests, it was observed that the developed actuator could generate larger actuation displacement than THUNDERT$^{TM}$.

Flame Resistance Performance of Glass Fiber and Polyester Fiber Architectural Membranes (건축용 유리섬유 및 폴리에스테르섬유 막재의 난연특성)

  • Kim, JiHyeon;Song, Hun
    • Fire Science and Engineering
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    • v.30 no.1
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    • pp.17-23
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    • 2016
  • Membrane structures can be used to create diverse lightweight structural forms using ductile membranes made of coated fabric. Using membrane structures, it is possible to construct large covered spaces relatively quickly and economically, and hence, they are being applied within various applications. The structures are light-weight, transparent, flexible in their application, economical and easy to maintain, and as such, their usage is being expanded. However, despite their prevalence, the standard for membrane material performance in terms of fire safety is still inadequate, and the development of membrane materials with excellent flame resistance performance is being demanded. This study determined flame resistance performance of architectural membranes, including PTFE, PVDF, PVF and ETFE film membranes, through flammability testing and incombustibility testing.

A Study on the Preparation of Tritium Luminous Compound

  • Kim, Jaerok
    • Nuclear Engineering and Technology
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    • v.4 no.4
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    • pp.331-339
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    • 1972
  • For the syntheses of tritium labelled polystyrene, the basic material for the preparation of tritium luminous compound, various methods of labelling such as Tesla discharge, Wilzbach exposure, gamma irradiation, and U V. irradiation were compared in view of getting high specific activity-product. The obtained polystyrene-T(G) by the method of Tesla discharge and by the method of U. V. irradiation had specific activity of 1~1.2 mCi/mg, and these two methods were the most encouraging. Mixing of 1 part of polystyrene-T(G) with 4 parts of ZnS:Cu phosphor, in weight, appeared to be the most suitable ratio in tile preparation of luminous compound in luminosity point of view. When 30 mg. of obtained luminescent mixture was applied on steel plate by using 1 ml. of the selected binder (i.e., 1g of commercial varnish in 100m1. of benzene) the luminosity maximum was ca. 20 micro Lambert. The prepared luminous compound was confirmed to be practically applicable for mine marker or dark-room light source.

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Performance Enhancement of Floating PV Generation Structure Using FRP (FRP를 활용한 부유식 태양광발전 구조시스템의 성능 향상)

  • Choi, Jin-Woo;Joo, Hyung-Joong;Nam, Jeong-Hun;Hwang, Seong-Tae;Yoon, Soon-Jong
    • Composites Research
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    • v.26 no.2
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    • pp.105-110
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    • 2013
  • In this study, we suggest the new floating PV generation structure which is improved the structural and economical efficiency compared with the system developed in the previous research. Pultruded FRP has superior physical and chemical material properties compared with those of conventional structural materials. Especially, pultruded FRP has an excellent corrosion-resistance, light-weight, and it also has high specific strength and stiffness which are highly appreciated for the design and fabrication of floating PV generation structure under harsh environmental condition. In this study, structural analysis using the finite element method has been performed to investigate the safety of new floating PV generation structure and newly applied structural members.

Effect of Hot-stamping on Microstructures and Tensile Properties of Al-Si Coated Boron Steel Welds with Laser Source (Al-Si 도금된 보론강 레이저 소스에 따른 레이저 용접부의 미세조직과 기계적 성질에 미치는 핫스탬핑 처리의 영향)

  • Oh, Myeong-Hwan;Kong, Jong-Pan;Kwon, Min-Suck;Kang, Chung-Yun
    • Journal of Welding and Joining
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    • v.31 no.6
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    • pp.96-106
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    • 2013
  • In this study, the effect of laser source($CO_2$ and Nd:YAG) on the microstructure and tensile properties of laser welded Al-Si coated boron steel(1.2mmt) was investigated with before and after hot-stamping. In case of as welds condition, fracture occurred in base metal unrelated to the laser source. It could be explained that tensile strength of fusion zone composed of martensite and bainite is higher than that of base metal that contains a lot of ferrite despite dilution of Al and Si from coating layer to fusion zone. In case of hot-stamping condition, the fracture occurred in fusion zone irrelevant to laser source and the tensile strength was lower than hot stamped base metal. In the $CO_2$ laser welds, $Fe_3$(Al,Si) formed near the bond line was transformed into ferrite during hot-stamping. Therefore tensile strength of bond line is lower than that of base metal and center of fusion zone and the fracture occurred in the bond line. On the other hand, in the Nd:YAG laser welds, the higher concentration of Al formed the ferrite in the fusion zone during hot-stamping treatment. Also, the thickness of centerline was thinner than that of base metal. Therefore, it is considered that fracture occurred in centerline of fusion zone due to effect of concentration stress, and it leaded to a lower tensile strength and elongation.

Analysis of Shear Behavior and Fracture Characteristics of Plywood in Cryogenic Environment (극저온 환경 하 플라이우드의 전단 거동 및 파손 특성 분석)

  • Son, Young-Moo;Kim, Jeong-Dae;Oh, Hoon-Kyu;Kim, Yong-Tai;Park, Seong-Bo;Lee, Jae-Myung
    • Journal of Ocean Engineering and Technology
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    • v.33 no.5
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    • pp.394-399
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    • 2019
  • Plywood is a laminated wood material where alternating layers are perpendicular to each other. It is used in a liquefied natural gas (LNG) carrier for an insulation system because it has excellent durability, a light weight, and high stiffness. An LNG cargo containment system (LNG CCS) is subjected to loads from gravity, sloshing impact, hydrostatic pressure, and thermal expansion. Shear forces are applied to an LNG CCS locally by these loads. For these reasons, the materials in an LNG CCS must have good mechanical performance. This study evaluated the shear behavior of plywood. This evaluation was conducted from room temperature ($25^{\circ}C$) to cryogenic temperature ($-163^{\circ}C$), which is the actual operating environment of an LNG storage tank. Based on the plywood used in an LNG storage tank, a shear test was conducted on specimens with thicknesses of 9 mm and 12 mm. Analyses were performed on how the temperature and thickness of the plywood affected the shear strength. Regardless of the thickness, the strength increased as the temperature decreased. The 9 mm thick plywood had greater strength than the 12 mm thick specimen, and this tendency became clearer as the temperature decreased.