• 제목/요약/키워드: flexible material

검색결과 1,047건 처리시간 0.031초

연성포장에서 노상재료로서 EPS지오폼의 회복탄성계수의 모델에 관한 분석적 연구 (Analytical Study on Resilient Modulus Model of Expanded Polystyrene(EPS) Geofoam as a Subgrade Material in Flexible Pavement)

  • 박기철;장용채
    • 한국지반환경공학회 논문집
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    • 제13권9호
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    • pp.61-68
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    • 2012
  • 본 연구의 주된 목적은 EPS지오폼이 연성포장의 노반재료로 사용될 때 그것의 회복탄성계수를 해석 모델화 하는 것이다. 이 해석모델은 삼축압축 시험으로부터 나온 실험결과를 토대로 만들어졌다. 그리고 이 모델은 원하는 용도에 따라서, 기존의 프로그램을 수정하거나 새로 개발하여 유한요소법을 이용한 연성포장구조를 해석하는데 사용될 수 있다. 또한 본 연구의 결과는 연성포장에서의 현장 연약지반 노상재료의 대체물로서 EPS지오폼은 적합한 것으로 확인되었다.

연질 FRP수지의 옥상주차장바닥 적용성 평가 연구 (A Study of Application Characteristic Evaluation Research of Flexible FRP Resin on the Roof and Floor of Parking Area)

  • 이형준;김성식;안상구;조아형;오상근
    • 한국건축시공학회:학술대회논문집
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    • 한국건축시공학회 2007년도 추계 학술논문 발표대회
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    • pp.129-132
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    • 2007
  • From this research the construction civil official is simple with the parking floor finishing material, it improves the durability of the parking floor it uses the flexible FRP it will be able to secure the drainage quality it is excellent and it presents the efficient application plan from the construction site. The performance appraisal only efficiency with of result floor of parking area material bay it knows, the result where also the performance appraisal portion re-with roof bottom finishing is satisfied it showed. The flexible FRP it applies the material to the building as to diminish the damage of the bottom finishing material due to the deterioration and the conduct and the external force of the building it is exposed to the external environment, secures the quality of the material from the construction site and will contribute to the stability against the bottom finishing material.

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미세 광학패턴기술을 이용한 Flexible Backlight에 관한 연구 (Investigation of flexible backlight using micro-scale optical function pattern design)

  • 한정민;서대식
    • 한국위성정보통신학회논문지
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    • 제9권1호
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    • pp.70-73
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    • 2014
  • 최근 휴대용 정보전자기기의 비약적인 사용의 증가는 충격에 보다 강한 디스플레이에 대한 연구를 발전시키는 계기가 되었다. 일부 제조회사에서 AMOLED를 사용한 디스플레이에서 유연한 특성을 가진 제품을 선보이고 있으나, 그 사용량에 있어서 압도적으로 많은 부분을 차지하고 있는 것은 LCD 이다. 특히 LCD는 구조적인 문제로 인하여 반드시 후면광원을 사용하여야 하는데, 면발광형식의 조광장치를 얇은 두께로 구현하는데 사용되는 것이 아크릴 재질의 도광판이다. 본 연구에서는 유연하지 않은 메틸메타아크릴레이트에 부틸 아크릴레이트 고무계열의 합성재료를 첨가하여 유연성을 유지하고, 투과율을 90%까지 상승시킨 KURARITY 라는 재질을 사용한 패턴의 설계 및 성형 결과를 통해서 유연한 후면광원의 가능성을 평가하는데 주력하였다. 평가 결과 기존의 광원과 동일한 수준의 밝기 및 휘도 균일도를 얻을 수 있었다.

플렉시블 디스플레이용 CNT 애노드 특성 및 이를 이용하여 제작한 플렉시블 OLED 특성 분석 (Characteristics of Carbon Nanotube Anode for flexible displays and characteristics of OLEDs fabricated on Carbon Nanotube Anode)

  • 김한기;정진아;문종민
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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    • pp.416-417
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    • 2007
  • We prepared flexible transparent conducting electrodes by spray coating of single-walled carbon nanotube (SWNT) networks on PET substrate and have demonstrated their use as transparent anodes for flexible organic light emitting diodes (OLEDs). The flexible CNT electrode produced by spray coating method shows relatively low sheet resistance ($150{\sim}220{\Omega}/sq.$) and high transmittance of ~60% even though it was prepared at room temperature. In addition, CNT electrode/PET sample exhibits little resistance change during 2000 bending cycles, demonstrated good mechanical robustness. Using transparent CNT electrode, it is readily possible to achieve performances comparable to commercial ITO-based OLEDs. This indicates that flexible CNT electrode is alternative anode materials for conventional ITO anode in flexible OLEDs.

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유연 반도체/메모리 소자 기술 (Technology of Flexible Semiconductor/Memory Device)

  • 안종현;이혁;좌성훈
    • 마이크로전자및패키징학회지
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    • 제20권2호
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    • pp.1-9
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    • 2013
  • Recently flexible electronic devices have attracted a great deal of attention because of new application possibilities including flexible display, flexible memory, flexible solar cell and flexible sensor. In particular, development of flexible memory is essential to complete the flexible integrated systems such as flexible smart phone and wearable computer. Research of flexible memory has primarily focused on organic-based materials. However, organic flexible memory has still several disadvantages, including lower electrical performance and long-term reliability. Therefore, emerging research in flexible electronics seeks to develop flexible and stretchable technologies that offer the high performance of conventional wafer-based devices as well as superior flexibility. Development of flexible memory with inorganic silicon materials is based on the design principle that any material, in sufficiently thin form, is flexible and bendable since the bending strain is directly proportional to thickness. This article reviews progress in recent technologies for flexible memory and flexible electronics with inorganic silicon materials, including transfer printing technology, wavy or serpentine interconnection structure for reducing strain, and wafer thinning technology.

Robust motion control of a flexible micro-actuator using $H_{\infty}$ control method

  • Okugawa, Masayuki;Sasaki, Minoru;Fujisawa, Fumio
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1996년도 Proceedings of the Korea Automatic Control Conference, 11th (KACC); Pohang, Korea; 24-26 Oct. 1996
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    • pp.397-400
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    • 1996
  • In this paper, robust motion control of a flexible micro-actuator is presented. The actuator is made of a bimorph piezoelectric high-polymer material (PVDF). No mathematical model system can exactly model a physical system such a flexible micro-actuator. For this reason we must be aware of how modeling errors might adversely affect the performance of a control system for such a model. The H method addresses a wide range of the control problems, combining the frequency and time domain approaches. The design is an optimal one in the sense of minimization of the maximum of the closed-loop transfer function. It includes colored measurement and process noise. It also addresses the issues of robustness due to model uncertainties, and is applicable to the, flexible micro-actuator control problem. Therefore, we adopt the H control problem to the robust motion control of the flexible micro-actuator. Theoretical and experimental results demonstrate the satisfactory performance and the effectiveness of the designed controller. the effectiveness of the designed controller.

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전단 대변형을 고려한 유연직물복합재료 해석 (Analysis of Flexible Textile Composites with Large Shear Deformation)

  • 서영욱;우경식;강왕구
    • 한국항공우주학회지
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    • 제36권8호
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    • pp.734-739
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    • 2008
  • 본 논문에서는 미시 및 중시 역학의 2-단계 해석 전략을 채택하여 유연직물 복합재료의 기계적 거동을 예측하였다. 미시역학에서는 섬유다발의 유효물성치를 계산하였고 그 결과를 이용해 중시역학에서 유연직물복합재료의 인장탄성계수를 예측하였다. 중시역학 해석 과정에서는 섬유다발의 회전 및 전단 대변형에 의한 기하학적 비선형성을 고려하기 위하여 사용자 정의 부프로그램을 개발하여 ABAQUS 내에 삽입하였다. 해석결과, 인장하중을 받는 유연직물복합재료의 응력-변형률은 비선형 거동을 보였고, 계산된 유효탄성계수는 시험값과 잘 일치하는 것으로 나타났다.

Ag thickness effect on electrical and optical properties of flexible IZTO/Ag/IZTO multilayer anode grown on PET

  • 남호준;조성우;김한기
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 추계학술대회 논문집
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    • pp.379-379
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    • 2007
  • The characteristics of indium-zinc-tin-oxide (IZTO)-Ag-IZTO multilayer grown on a PET substrate were investigated for flexible organic light-emitting diodes. The IZTO-Ag-IZTO (IAI) multilayer anode exhibited a remarkably reduced sheet resistance of 4 ohm/sq and a high transmittance of 84%, despite the very thin thickness of the IZTO (30 nm) layer. In addition, it was shown that electrical and optical properties of IAI anodes are critically dependent on the thickness of the Ag layer, due to the transition of Ag atoms from distinct islands to continuous films at a critical thickness (14 nm). Moreover, the IAI/PET sample showed more stable mechanical properties than an amorphous ITO/PET sample during the bending test due to the existence of a ductile Ag layer. The current density voltage-luminance characteristics of flexible OLEDs fabricated on an IAI/PET substrate was better than those of flexible OLEDs fabricated on an ITO/PET substrate. This indicates that IAI multilayer anodes are promising flexible and transparent electrodes for flexible OLEDs.

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Process Modeling of Flexible Robotic Grinding

  • Wang, Jianjun;Sun, Yunquan;Gan, zhongxue;Kazerounian, Kazem
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2003년도 ICCAS
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    • pp.700-705
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    • 2003
  • In this paper, an extended process model is proposed for the application of flexible belt grinding equipment as utilized in robotic grinding. The analytical and experimental results corresponding to grinding force, material removal rate (MRR) and contact area in the robotic grinding shows the difference between the conventional grinding and the flexible robotic grinding. The process model representing the relationship between the material removal and the normal force acting at the contact area has been applied to robotic programming and control. The application of the developed model in blade grinding demonstrates the effectiveness of proposed process model.

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Finite element application of an incremental endochronic model to flexible pavement materials

  • Kerh, Tienfuan;Huang, C.Y.
    • Structural Engineering and Mechanics
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    • 제6권7호
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    • pp.817-826
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    • 1998
  • A finite element model based on the incremental endochronic theory for flexible pavement materials was developed in this study. Three grid systems with eight-node cubic isoparametric elements, and different loading steps were used to perform the calculations for a specimen of circular cylinder. The uniaxial stress experimental results on an asphalt mixture at $60^{\circ}C$ in SHRP conducted by University of California at Berkeley were used to check the ability of the derived numerical model. Then, the numerical results showed isotropic response and deviatoric response on the specimen in a three dimensional manner, which provided a better understanding for a deformed flexible material under the specified loading conditions.