• Title/Summary/Keyword: 강화재 방향

Search Result 170, Processing Time 0.037 seconds

'97실무건축계의 자화상

  • Korea Institute of Registered Architects
    • Korean Architects
    • /
    • no.7 s.339
    • /
    • pp.31-56
    • /
    • 1997
  • 오늘날 건축계는 정치ㆍ경제ㆍ사회적 혼돈 상황 못지 않게 지난 몇 해 이래 혼란의 와중에서 벗어나지 못하고 있다. 설계시장의 대외개방, 행정개혁에 따른 건축관계법령 정비, 연이은 대형사고에 따른 감리업무 강화 및 건축사의 책임증대, 건설업계의 설계영역 진출 시도, 경기불황에 따른 설계사무소의 경영압박 및 부익부 빈익빈 현상 심화, 과열된 수주경쟁과 건축사의 윤리의식에 대한 논쟁, 전문직으로서의 건축사 역할과 사회 대중적 요구간의 갈등. 이렇듯 혼돈과 혼란의 상황이 계속되고 있는 건축계의 현실을 바라다보는 건축 각 실무분야의 시각 또한 연령과 지역, 사무소의 규모, 작업형태, 개인적 철학이나 건축관 등에 따라 다양할 수 밖에 없을 것이다. 이에 본지는 오늘날 실무건축계가 처한 현실을 재진단하고 나아가 미래의 모습을 함께 생각해 보고자 '97실무건축계의 자화상'이란 주제로 각 실무분야를 배경으로 실질적 관심사항과 실무건축계의 긍정적ㆍ부정적 모습은 물론 해결되어져야 할 문제점, 나아갈 방향 등에 대해 다양하고도 진솔한 목소리를 들어보고자 한다.

  • PDF

Characterization of CNT/Polymer Nanocomposites using MD-based Multiscale Method (분자동역학에 기반한 멀티스케일 해석을 이용한 탄소나노튜브/고분자 복합재료의 특성 규명)

  • Yu, Su-Young;Yang, Seung-Hwa;Cho, Maeng-Hyo
    • Proceedings of the Computational Structural Engineering Institute Conference
    • /
    • 2010.04a
    • /
    • pp.554-557
    • /
    • 2010
  • 본 논문에서는 동일한 체적분율 가지는 탄소나노튜브 나노복합재의 기계적 특성을 규명하였다. 동일한 chirality를 가지는 서로 다른 크기의 탄소나노튜브를 이용하여 탄소나노튜브의 크기가 복합재의 물성에 미치는 영향을 규명하였다. 복합재료의 분자동역학의 결과 탄소나노튜브의 길이방향의 물성은 크게 증가하나, 전단특성의 물성 강화효과를 나타나지 않았다. 이는 통해 탄소나노튜브와 기지재료 사이의 상호작용력이 복합재료의 전단력을 전달하고, 변형을 유지할 만큼 강하지 않다는 것을 확인하였다. 이와 같은 분자동역학 결과를 바탕으로 멀티스케일 모델을 개발하여 복합재료에서 나타나는 현상을 묘사하였다. 제안된 멀티스케일 모델을 이용하여 다양한 조건의 복합재료에 대한 특성 예측이 가능하다.

  • PDF

대구경 광학탑재체 광구조부의 길이 안정성 측정장치

  • Yeon, Jeong-Heum;Lee, Eung-Sik;Jang, Su-Yeong;Lee, Deok-Gyu
    • The Bulletin of The Korean Astronomical Society
    • /
    • v.37 no.2
    • /
    • pp.227.2-227.2
    • /
    • 2012
  • 대구경 고해상도 광학탑재체의 광구조부는 주반사경과 부반사경 등을 포함한 주요 광학부품들과 검출기를 포함한 초점면 조립부 등을 고정 지지해주는 부분으로, 발사시 전달되는 진동 및 우주 열환경하에서의 길이 안정성을 광학성능 범위내로 유지하여야 한다. 광학탑재체의 성능에 가장 큰 영향을 미치는 것은 주반사경과 부반사경의 광축방향의 길이 안정성으로, 광학탑재체의 작동 온도범위 내에서 수 마이크로미터 내외로 안정성이 요구된다. 이를 실현하기 위하여 주반사경과 부반사경의 간격은 열 및 흡습에 둔감한 탄소섬유 강화수지 복합재로 되어 있는 경통 구조물로 설계, 제작된다. 제작된 경통구조물의 길이 안정성을 검증하기 위해서는 별도의 정밀 측정장치가 필요하게 된다. 본 논문에서는 이러한 길이 안정성 측정장치에 대해 기술한다. 온도에 대해 변화가 거의 없는 (CTE<0.1ppm/K) Zerodur 소재의 막대 구조물을 기준 스케일로 삼았고, 이를 지지하기 위해 Invar 소재의 구조물을 사용 하였다. 주반사경의 베젤부위와 부반사경의 접속부위의 변위 변화를 세점에서 측정하여 길이 안정성을 측정할 수 있게 하였다.

  • PDF

The Pharmaceuticals Regime in the KORUS FTA and the TPP Agreement: A Comparative Analysis (한미FTA와 TPP협정의 비교분석을 통한 의약품 분야 국제통상규범에 대한 연구)

  • Yun, Mikyung
    • International Commerce and Information Review
    • /
    • v.18 no.4
    • /
    • pp.165-193
    • /
    • 2016
  • This paper conducts a comparative analysis of the KORUS FTA and the TPP Agreement to assess the current state of affairs in international trade rules for the pharmaceutical industry. Intellectual property rights as well as public health related regulations have evolved to strengthen the position of innovator drug companies. In particular, the TPP Agreement which adopted data exclusivity for biologics for the first time, will set the standard for the future. Apart from this however, the TPP Agreement has not gone further than the KORUS FTA and in some respects, even contains greater policy flexibilities and provisions for market access than the KORUS FTA. Korea should take advantage of such differences when and if she must engage in negotiations to join the TPP Agreement or a renegotiation of the KORUS FTA.

  • PDF

Reliability and Sensitivity Analysis for Laminated Composite Plate Using Response Surface Method (반응면 기법을 이용한 복합재 평판의 신뢰도 및 민감도해석)

  • Lee, Seokje;Jang, Moon-Ho;Kim, Jae-Ki;Moon, Jung-Won;Kim, In-Gul
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.37 no.4
    • /
    • pp.461-466
    • /
    • 2013
  • Advanced fiber-reinforced laminated composites are widely used in various fields of engineering to reduce weight. The material property of each ply is well known; specifically, it is known that ply is less reliable than metallic materials and very sensitive to the loading direction. Therefore, it is important to consider this uncertainty in the design of laminated composites. In this study, reliability analysis is conducted using COMSOL and MATLAB interactions for a laminated composite plate for the case in which the tip deflection is the design requirement and the material property is a random variable. Furthermore, the efficiency and accuracy of the approximation method is identified, and a probabilistic sensitivity analysis is conducted. As a result, we can prove the applicability of the advanced design method for the stabilizer of an underwater vehicle.

Prediction of Spring Rate and Initial Failure Load due to Material Properties of Composite Leaf Spring (복합재 판스프링의 재료특성에 따른 스프링 강성변화와 초기 파단하중 예측)

  • Oh, Sung Ha;Choi, Bok Lok
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.38 no.12
    • /
    • pp.1345-1350
    • /
    • 2014
  • This paper presented analysis methods for adapting E-glass fiber/epoxy composite (GFRP) materials to an automotive leaf spring. It focused on the static behaviors of the leaf spring due to the material composition and its fiber orientation. The material properties of the GFRP composite were directly measured based on the ASTM standard test. A reverse implementation was performed to obtain the complete set of in-situ fiber and matrix properties from the ply test results. Next, the spring rates of the composite leaf spring were examined according to the variation of material parameters such as the fiber angles and resin contents of the composite material. Finally, progressive failure analysis was conducted to identify the initial failure load by means of an elastic stress analysis and specific damage criteria. As a result, it was found that damage first occurred along the edge of the leaf spring owing to the shear stresses.

Development of Simulation Architecture Framework for Simulation Based Acquisition (모의기반획득을 위한 시뮬레이션 아키텍처 프레임워크 개발)

  • Cho, Kyu-Tae;Shim, Jun-Yong;Lee, Yong-Heon;Lee, Seung-Young;Kim, Sae-Hwan
    • Journal of the Korea Society for Simulation
    • /
    • v.19 no.3
    • /
    • pp.81-89
    • /
    • 2010
  • Recent modeling and simulation technology is being used in various fields. Especially in the field of military, Simulation-Based Acquisition (SBA) is recognized as a essential policy. To effectively carry out SBA, modeling and simulation techniques should be applied in the whole life-cycle for the weapon system development, and simulation architecture framework which provides easily reusable and interoperability is needed. Through reusability and interoperability, the costs of constructing the integrated collaborate environment for simulation based acquisition can be minimized. In this study, we define requirements, issues for enhancing reusability and interoperability, and propose simulation framework as a solution of the problem including structural design. Proposing simulation framework provides common functions for producing simulator as reusable units and easily changeable structure on user's purpose. In addition, we provide the result for applying simulation framework to our project.

On the Modification of a Classical Higher-order Shear Deformation Theory to Improve the Stress Prediction of Laminated Composite Plates (적층평판의 응력해석 향상을 위한 고전적 고차전단변형이론의 개선)

  • Kim, Jun-Sik;Han, Jang-Woo;Cho, Maeng-Hyo
    • Journal of the Computational Structural Engineering Institute of Korea
    • /
    • v.24 no.3
    • /
    • pp.249-257
    • /
    • 2011
  • In this paper, an systematic approach is presented, in which the mixed variational theorem is employed to incorporate independent transverse shear stresses into a classical higher-order shear deformation theory(HSDT). The HSDT displacement field is taken to amplify the benefits of using a classical shear deformation theory such as simple and straightforward calculation and numerical efficiency. Those independent transverse shear stresses are taken from the fifth-order polynomial-based zig-zag theory where the fourth-order transverse shear strains can be obtained. The classical displacement field and independent transverse shear stresses are systematically blended via the mixed variational theorem. Resulting strain energy expressions are named as an enhanced higher-order shear deformation theory via mixed variational theorem(EHSDTM). The EHSDTM possess the same computational advantage as the classical HSDT while allowing for improved through-the-thickness stress and displacement variations via the post-processing procedure. Displacement and stress distributions obtained herein are compared to those of the classical HSDT, three-dimensional elasticity, and available data in literature.

An Experimental Study of Fatigue and Static Behavior for Composite Deck Member (복합재료 바닥판 부재의 정적 및 피로거동에 관한 시험적 연구)

  • Kim, Doo-Hwan;Kim, Young-Chan
    • Journal of the Korean Society of Hazard Mitigation
    • /
    • v.11 no.2
    • /
    • pp.15-21
    • /
    • 2011
  • It is required to accumulate experimental datum that make the theories easy to general technicians in order to use composite material widely on construction field. Therefore, we intend to present base technologies that evaluate static and fatigue performance according to the FRP deck section and offer the basis datum for FRP deck analyses and the design standards. As results of static tests, it can be shown that specimen with fabric direction has higher rigidity than that with normal to fabric direction and convergence for the datum. Due to this reason, it has more stable behavior by structural characteristics of matrix arrangement during destruction. For the fatigue tests, we found that by increasing the number of test repetition, test specimen with fabric direction had an crack just before the destruction, and the contact surface was detached.

A Preliminary Study on Domestic Embracement and Development Plan Regarding UNESCO World Heritage Programme (유네스코 세계유산 제도의 우리나라 문화재 정책에의 수용과 발전방안에 대한 시론적 연구)

  • Kang, Kyung Hwan;Kim, Chung Dong
    • Korean Journal of Heritage: History & Science
    • /
    • v.43 no.1
    • /
    • pp.56-85
    • /
    • 2010
  • UNESCO World Heritage Programme was introduced following the adoption of Convention Concerning the Protection of the World Cultural and Natural Heritage by the General Conference of UNESCO in 1972 in order to protect cultural and natural heritage with superb value for all mankind. Despite its short history of less than 40 years, it has been evaluated as one of the most successful of the cultural area projects of UNESCO with 890 world heritage registered worldwide. For systematic protection management of World Heritage, UNESCO, through systemization of registration, emphasis on the importance of preservation management plan, institutionalization of monitoring, and operation of World Heritage Fund, has utilized World Heritage Programme not just as a means of listing excellent cultural properties, but as a preservation planning tool, and accordingly, such policies have had a significant influence on the cultural heritage protection legislations of numerous nations. Korea has ratified World Heritage Convention in 1988, and with the registration of the Royal Tombs of the Joseon Dynasty in 2009, it has 9 World Heritage Sites. Twenty years have passed since Korea joined the World Heritage Programme. While World Heritage registration contributed to publicity of the uniqueness and excellence of Korean cultural properties and improvement of Korea's national culture status, it is now time to devise various legislative/systematic improvement means to reconsider the World Heritage registration strategy and establish a systematic preservation management system. While up until now, the Cultural Properties Protection Law has been amended to arrange for basic rules regarding registration and protection of World Heritage Sites, and some local governments have founded bodies exclusive for World Heritage Site management, a more fundamental and macroscopic plan for World Heritage policy improvement must be sought. Projects and programs in each area for reinforcement of World Heritage policy capacity such as: 1) Enactment of a special law for World Heritage Site preservation management; 2) enactment of ordinances for protection of World Heritage Sites per each local government; 3) reinforcement of policies and management functionality of Cultural Heritage Administration and local governments; 4) dramatic increase in the finances of World Heritage Site protection; 5) requirement to establish plan for World Heritage Site preservation protection; 6) increased support for utilization of World Heritage Sites; 7) substantiation and diversification of World Heritage registration; 8) sharing of information and experiences of World Heritage Sites management among local governments; 9) installation of World Heritage Sites integral archive; 10) revitalization of citizen cooperation and resident participation; 11) training specialized resources for World Heritage Sites protection; 12) revitalization of sustainable World Heritage Sites tourism, must be selected and promoted systematically. Regarding how World Heritage Programme should be domestically accepted and developed, the methods for systemization, scientific approach, and specialization of World Heritage policies were suggested per type. In the future, in-depth and specialized researches and studies should follow.