• 제목/요약/키워드: Large deflection

검색결과 513건 처리시간 0.037초

IPMC의 동적 특성 (Dynamic Characteristics of Ionic-Polymer-Metal-Composite)

  • 전진한;신동군;이관호;오일권
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2005년도 춘계학술대회논문집
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    • pp.356-359
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    • 2005
  • Ionic-polymer-metal-composite(IPMC), one of new actuation materials of electroactive polymers plated with noble metallic electrodes is known for the fast bending upon electric field. The IPMC strip bends towards anode under electrical field. It has many merits of low driving voltage, quick responsiveness, high durability, possibility of miniaturizability. In this paper, we studied for developing the large deflection of IPMC according several fabricating parameters. We measured the large deflection by the different process of sandpaper and sandblasting in surface treatment, the initial compositing process and the surface electroding process, and the different counter ions in ion exchanging process. In fundamental, the displacement of IPMC strip depends on voltage magnitude and applied signal frequency and its maximum deformation is observed at a critical frequency, resonant frequency.

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Nonlinear Finite Element Analysis of Composite Shell Under Impact

  • Cho, Chong-Du;Zhao, Gui-Ping;Kim, Chang-Boo
    • Journal of Mechanical Science and Technology
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    • 제14권6호
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    • pp.666-674
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    • 2000
  • Large deflection dynamic responses of laminated composite cylindrical shells under impact are analyzed by the geometrically nonlinear finite element method based on a generalized Sander's shell theory with the first order transverse shear deformation and the von-Karman large deflection assumption. A modified indentation law with inelastic indentation is employed for the contact force. The nonlinear finite element equations of motion of shell and an impactor along with the contact laws are solved numerically using Newmark's time marching integration scheme in conjunction with Akay type successive iteration in each step. The ply failure region of the laminated shell is estimated using the Tsai- Wu quadratic interaction criteria. Numerical results, including the contact force histories, deflections and strains are presented and compared with the ones by linear analysis. The effect of the radius of curvature on the composite shell behaviors is investigated and discussed.

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차세대 유기 EL 디스플레이를 위한 기판 조작에 관한 연구 (Study on a large-size glass substrate handler for new generation OLED)

  • 김숙한;이동은;김준철;이응기
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2006년도 춘계학술대회 논문집
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    • pp.79-80
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    • 2006
  • In order to raise productivity of the OLED and realization of the OLED TV, it is required to improve the design of the board size glass panel. The large-size glass substrate has some difficulties regarding its deflection during handling operation due to its small thickness (0.7t) which is not even enough to stand its mass itself. This paper is demonstrating a new solution of this difficult through clamping and bending end condition, which helps to minimize the deflection of the glass substrate.

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Combined effects of material properties and boundary conditions on the large deflection bending analysis of circular plates on a nonlinear elastic foundation

  • Altekin, Murat
    • Computers and Concrete
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    • 제25권6호
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    • pp.537-549
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    • 2020
  • Geometrically nonlinear axisymmetric bending analysis of shear deformable circular plates on a nonlinear three-parameter elastic foundation was made. Plates ranging from "thin" to "moderately thick" were investigated for three types of material: isotropic, transversely isotropic, and orthotropic. The differential equations were discretized by means of the finite difference method (FDM) and the differential quadrature method (DQM). The Newton-Raphson method was applied to find the solution. A parametric investigation using seven unknowns per node was presented. The novelty of the paper is that detailed numerical simulations were made to highlight the combined effects of the material properties and the boundary conditions on (i) the deflection, (ii) the stress resultants, and (iii) the external load. The formulation was verified through comparison studies. It was observed that the results are highly influenced from the boundary conditions, and from the material properties.

카스틸리아노 정리를 이용한 개선된 메카넘 휠의 롤러 축의 처짐에 대한 연구 (A Study on the Deflection of Roller Axis of an Improved Mecanum Wheel Using the Castigliano Theorem)

  • 황희건;정원지;김대영
    • 한국기계가공학회지
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    • 제19권6호
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    • pp.61-66
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    • 2020
  • For simple and repetitive transport tasks in limited spaces such as in factories, it is more efficient to use mobile robots instead of human workers. For this reason, the reliance on mobile robots is increasing due to the increased implementation of smart factories. Currently, the structural design of the Mecanum wheel is required to ensure the stability of the moving robot since it is used for the transport of not only small products but also large products. In this paper, to improve the stability and durability of the Mecanum wheel, ways to improve the structure of the Mecanum wheel are presented. Then, using the Castigliano theorem, the structural stability is reviewed through the deflection on existing and improved structures.

펜슬가공시 공구변형을 고려한 볼엔드밀이 가공 궤적 (Tool Trajectory of Ball-End Mill in Consideration of Deflection when Pencil Cutting)

  • 윤경석
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 1997년도 추계학술대회 논문집
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    • pp.88-93
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    • 1997
  • Ball-end milling process is widely used in the die and mold manufacturing because of suitable for the machining of free-form surface. Pencil cutting can eliminate overload in uncut area caused by large diameter of ball-end mill before finish cutting. As the ball-end mill for pencil cutting is long and thin, it is easily deflected by cutting force. The tool deflection when pencil cutting is one of the main reason of the machining errors on a free-from surface. The purpose of the research is to find out the characteristics of deflected cutter trajectory by eddy-current sensor.

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볼엔드밀에 의한 펜슬가송시 공구변형 특성 (Characteristics of Tool Deflection when Pencil Cutting with Ball-End Mill)

  • 윤경석;왕덕현;이윤경;이상훈
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 1995년도 추계학술대회 논문집
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    • pp.157-160
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    • 1995
  • Pencil cutting can eliminate overload in uncut area caused by large diameter ball-end mill before finish cutting. As ball-end mill for pencil cutting is long and type, it is easily deflected by cutting force. The tool deflection when pencil cutting with thin and long ball-end mill is one of the main reason of the machining errors on a free-form surface. The purpose of the research is to find the characteristics of deflected cutter trajectory by eddy-current sensor.

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초기 처짐현상을 고려한 조강형 콘크리트의 탄성계수 발현 특성 연구( I ) (The Development Characteristic of Modulus of Elasticity in High Early Strength Concrete Considering Early Deflection( I ))

  • 이웅종;엄태선;이종열;홍건호
    • 한국콘크리트학회:학술대회논문집
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    • 한국콘크리트학회 2009년도 춘계 학술대회 제21권1호
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    • pp.317-318
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    • 2009
  • 본 연구는 건축물의 공기단축을 위하여 조기 거푸집 탈형으로 인한 과대 처짐이 예측될 경우를 고려한 조강형 콘크리트의 탄성계수 발현특성을 실험실적으로 확인하였다. 연구결과, 조강형 콘크리트는 보통 콘크리트에 비하여 처짐에 대하여 유리함 것으로 평가되었다.

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단결정 구리 나노와이어의 굽힘 특성 (Bending Characteristics of Single Crystalline Copper Nanowires)

  • 정광섭;조맹효
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2008년도 추계학술대회A
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    • pp.1896-1901
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    • 2008
  • Single crystalline copper nanowires are subjected to bending tests using molecular dynamics simulations and the embedded atom method. To observe behaviors of nanowire, bending tests are performed for various rates of deflection and different boundary conditions: fixed-free and fixed-fixed. When the deflection of nanowire becomes large, twinnings and dislocations appear, and <100> crystal structure transforms to <110>. At high rates, phase transformation occurs in whole nanowire. But, at low rates, atomic structure changes to <110> phase partially. The final deformed structures are affected by the rate of deflection and boundary conditions. These effects can be important design parameters at nanoscale.

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차체용 드로우 다이의 블랭크 홀더 굽힘 변형 해석 (Analysis on the Bending Deflection of the Blank Holder in Automotive Body Panel Draw Die)

  • 인정제;신용승;김헌영;김재우;송명환;박진수
    • 한국공작기계학회:학술대회논문집
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    • 한국공작기계학회 2000년도 추계학술대회논문집 - 한국공작기계학회
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    • pp.249-254
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    • 2000
  • The contact forces between die components for the drawing of large size automotive panels introduce elastic deflections of the die components. Due to the deflections, the gap between blank holder and die varies locally resulting in nonuniform material flow. Such a nonuniform die gap usually requires correcting operation, so called die spotting, which is time consuming trial and error process. To reduce the die spotting time, the optimization of the blank holder bending deflection is needed. In this paper, we implemented an analysis procedure to predict the blank holder deflection. The analysis procedure and design of experiments techniques are applied to the optimization of balance block heights. The optimization results can be used as guidelines in actual die spotting process.

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