• Title/Summary/Keyword: bending deflection

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Relationship between Plane and Side Drape Coefficient of Fabrics (직물의 평면 드레이프 계수와 측면 드레이프 계수와의 관계)

  • 서정권;이정욱
    • Journal of the Korean Society of Clothing and Textiles
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    • v.20 no.3
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    • pp.519-526
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    • 1996
  • To investigate the relationship between plane and side drape coefficient, the drape tester designed in which coordinate of projected outline of draped specimen could be recorded. By using this drape tester, the three dimensional shape, plane and side drape coefficient were obtained from coordinate of plane projected shape, and furthermore examined the tendency in changes of drape coefficient in terms of diameter of specimen, deflection angle, and bending rigidity. The side drape coefficients were constant regardless of changes in diameter of specimen. The plane drape coefficients, however, made a little difference according to changes in diameter of specimen. The experimental drape coefficient agreed well with the theoretical drape coefficient according to deflection angle. In the meanwhile, when the plane drape coefficients were regressed with the side drape coefficents, regression equation was $y=0.375x-0.002x^2+6.9\times10^{-5}x^3$. When the $\overline{\theta_s}$ is mean of deflection angle of selected points which have the longest and shortest distance from center point in the node, the theoretical drape coefficient calculated from $\overline{\theta_s}$ has high correlation with experimental drape coefficient. The plane and side drape coefficient changed linearly with increasing the bending length, $\sqrt[3]{EI/w}$.

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Mechanical Properties of Cucumber under Bending Force (휨하중(荷重)을 받는 오이의 역학적(力學的) 특성(特性))

  • Kim, M.S.;Song, C.H.;Park, J.M.
    • Journal of Biosystems Engineering
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    • v.18 no.1
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    • pp.30-36
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    • 1993
  • Cucumbers being living biological materials are generally vulnerable to external forces, especially, bending force during the processes, because they have usually longish shape. Understanding the mechanical and viscoelastic properties of cucumber is important to analyze various characteristics which might be helpful in determining design parameters for the processing equipment such as sorting, packaging and transporting machine. The objectives of this study were to determine ultimate bending strength, deflections, and hysteresis losses for the cucumbers from the bending tests. Within the range of loading rate from 20 to 100mm/min, the ultimate bending strength of the cucumber samples were 525-630kPa at the Gyeousalicheongjang and the Baekdadagi, and 476~618kPa at the Cheongjangmadi, respectively, but the ultimate bending deflection ratio of the Cheongjangmadi showed the highest value among the tested samples. The effect of loading rate on the physical properties of the cucumber was relatively significant, all considered physical properties and degree of elasticity of the cucumber increased with the loading rate, but the hysteresis loss decreased with it.

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Experimental Investigation of Shear Modulus of a Core in a Metallic Sandwich Plate with a Truss Core (트러스형 금속 샌드위치 판재에서 심재의 전단특성계수의 실험적 결정)

  • Jung, Chang-Gyun;Seong, Dae-Young;Yang, Dong-Yol;Moon, Kyung-Je;Ahn, Dong-Gyu
    • Journal of the Korean Society for Precision Engineering
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    • v.24 no.8 s.197
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    • pp.67-73
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    • 2007
  • A sandwich plate with a truss core is composed of two face sheets and a pyramidal truss core between face sheets. This paper shows how to estimate the shear modulus of a truss core, experimentally. To determine the shear modulus of truss cores, 3-point bending tests are performed. For tests, metallic sandwich beams with truss cores are fabricated. Two kinds of truss cores are tested to investigate the shear modulus. Each test is repeated under different widths in order to increase accuracy. As a result, the shear modulus of sandwich beam is properly calculated. The deflection of a sandwich beam with a truss core by shear deformation takes the major contribution of the total deflection and the shear modulus of sandwich beam should be considered whenever it is designed.

Analytical Study of Reinforced Concrete Beams Strengthened with Fiber Reinforced Plastic Laminates (적층판으로 보강된 철근콘크리트보에 대한 해석적 연구)

  • Chae, Seoung-Hun;Kang, Joo-Won
    • 한국공간정보시스템학회:학술대회논문집
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    • 2004.05a
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    • pp.206-211
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    • 2004
  • This paper deals with the flexural strengthening of reinforced concrete beams by means of thin fiber reinforced plastic(FRP) laminas. This study focuses on modeling of structural of concrete bonded FRP laminate in flexural bending members. Used computational equation is derived by relation of stress and strain. The section analysis is based on experimental observations of a linear strain distribution in the cross section until failure, and a multi-linear moment-deflection curve that is divided into four regions, each terminated by a similarly numbered point. The load-deflection relationship in each region is assumed to be linear. The present model is validated to compare wit the experiment of 4-point bending tests of R/C rectangular beams strengthened with CFRP laminates, and has well predicted the moment-displacement relationships of members.

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

  • Kim Soak-Han;Lee Dong-Eun;Kim Jun-Chul;Lee Eung-Ki
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2006.05a
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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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Exact Solution on the Vertical Hydro-elastic Responses of Ships having Uniform Sectional Properties (균일단면 선박의 유탄성 수직응답에 대한 해석해)

  • Park, In-Kyu;Jung, Jong-Jin;A. Korobkin
    • Journal of the Society of Naval Architects of Korea
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    • v.41 no.2
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    • pp.47-54
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    • 2004
  • Exact solution on the vertical responses of ships having uniform sectional properties in waves is derived. Boundary value problem consisted of Timoshenko beam equation and free-free end condition is solved analytically. The responses are assumed as linear and wave loads are calculated by using strip method. Vertical bending moment, shear force and deflection are calculated. The developed analysis model is used for the benchmark test of the numerical codes in this problem. Also the application on the preliminary design of barge-like ships and VLFS (Very Large Floating Structure) is expected.

A new finite element formulation for vibration analysis of thick plates

  • Senjanovic, Ivo;Vladimir, Nikola;Cho, Dae Seung
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.7 no.2
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    • pp.324-345
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    • 2015
  • A new procedure for determining properties of thick plate finite elements, based on the modified Mindlin theory for moderately thick plate, is presented. Bending deflection is used as a potential function for the definition of total (bending and shear) deflection and angles of cross-section rotations. As a result of the introduced interdependence among displacements, the shear locking problem, present and solved in known finite element formulations, is avoided. Natural vibration analysis of rectangular plate, utilizing the proposed four-node quadrilateral finite element, shows higher accuracy than the sophisticated finite elements incorporated in some commercial software. In addition, the relation between thick and thin finite element properties is established, and compared with those in relevant literature.

Analysis and Design Programming of RC Beams Strengthened with Carbon Fiber Sheets (탄소섬유시트로 보강된 RC보의 해석 및 설계 프로그램 개발)

  • 김성도;김성수
    • Journal of the Korean Society for Railway
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    • v.7 no.4
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    • pp.319-325
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    • 2004
  • In this study, analysis and design programs of bending of RC beams strengthened with fiber sheets are developed by using Visual Basic Language. The program consists two groups, ultimate strength method and nonlinear flexural analysis method. Ultimate strength method regards concrete compressive stress as a rectangular stress block and do not consider tensile stress of concrete and load-deflection curves. On the other hand, nonlinear flexural analysis considers tensile stress of concrete, load-deflection curves, state of stress distribution and failure strain of strengthening material. Also, the analysis method used in this study regards nonlinear flexural stress as compressive stress of concrete. This program can be a good tool for determining the bending strength of strengthened RC beams and estimating the amount of fiber sheets for practical use.

Prediction of Lateral Deflection and Maximum Bending Moment of Model Piles Using Artificial Neural Network (인공 신경망을 이용한 모형말뚝의 수평변위와 최대 휨모멘트 예측)

  • 김병탁;김영수;이우진
    • Journal of the Korean Geotechnical Society
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    • v.16 no.5
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    • pp.169-178
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    • 2000
  • 본 논문에서는 단일 및 군말뚝의 수평변위와 최대 휨모멘트를 예측하기 위하여 인공신경망을 도입하였다. 인공신경망에 의한 결과는 낙동강 모래지반에서 단일 및 군말뚝에 대하여 수행한 일련의 모형실험결과와 비교하였다. 인공신경망 중의 하나인 오류 역전파 신경망(EBIPNN)의 적용성 검증을 위하여 600개의 모형실험결과들을 이용하였다. 그리고 신경망의 구조는 한개의 입력층과 두개의 은닉층 그리고 한개의 출력층으로 구성되었다. 전체 데이터의 25%, 50% 그리고 75% 결과는 각각 신경망의 학습에 이용되었으며 학슴에 이용하지 않은 데이터들은 예측에 이용되었다. 인공신경망 학습결과와 실험결과의 비교에 의하면, 신경망의 최적학습을 위하여 최적학습을 위하여 적합한 은닉층의 뉴런수는 각각 30개로 그리고 학습률은 0.9로 결정되었다. 전체 데이터의 50%이상으로 학습을 수행한 신경망의 모델은 정확한 예측을 하는 것으로 나타났다. 따라서, 인공신경망 모델리 수평하중을 받는 말뚝의 수평변위와 최대 휨모멘트의 예측에 적용될 수 있는 가능성을 보여주었다.

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Experimental tests on biaxially loaded concrete-encased composite columns

  • Tokgoz, Serkan;Dundar, Cengiz
    • Steel and Composite Structures
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    • v.8 no.5
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    • pp.423-438
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    • 2008
  • This paper reports an experimental investigation of the behaviour of concrete-encased composite columns subjected to short-term axial load and biaxial bending. In the study, six square and four L-shaped cross section of both short and slender composite column specimens were constructed and tested to examine the load-deflection behaviour and to obtain load carrying capacities. The main variables in the tests were considered as eccentricity of applied axial load, concrete compressive strength, cross section, and slenderness effect. A theoretical procedure considering the nonlinear behaviour of the materials is proposed for determination of the behaviour of eccentrically loaded short and slender composite columns. Two approaches are taken into account to describe the flexural rigidity (EI) used in the analysis of slender composite columns. Observed failure mode and experimental and theoretical load-deflection behaviour of the specimens are presented in the paper. The composite column specimens and also some composite columns available in the literature have been analysed and found to be in good agreement with the test results.