• Title/Summary/Keyword: thickness direction

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Coater Die Design and Coating Quality Evaluation in the Machine Direction of Slot Coating Through Computer Simulation (컴퓨터 해석을 통한 Slot 코팅공정에서 운전방향의 코팅품질 평가 및 다이 설계)

  • Kim, T.H.;Lee, D.Y.;Sung, D.J.;Lyu, M.Y.
    • Elastomers and Composites
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    • v.48 no.4
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    • pp.282-287
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    • 2013
  • Slot coating has been widely spread in photo resist coating on glass for flat display monitor. High quality of coating is required as high quality of image in display is needed. Coating quality in the slot coating is divided into nozzle direction quality and machine direction quality. Nozzle direction quality is related to flow uniformity inside the die whereas machine direction quality is related to die lip design and operational conditions. In this study coating uniformity in the machine direction of slot coating has been investigated through computer simulation. Die lip angle and die lip length were considered as outside die geometry and coating speed was considered as operational condition. Coating behavior has been analyzed and coating quality has been evaluated through computer simulation. Coating thickness decreased and coating uniformity increased as coating speed increased. However, the stability of meniscus formation was reduced and subsequently coating stability was reduced as coating speed increased. Coating thickness deviation decreased as die lip angle increased in down stream die. Coating thickness decreased and time to reaching steady state increased as increased die lip length in down stream die.

Microstructural Evolution Analysis in Thickness Direction of An Oxygen Free Copper Processed by Accumulative Roll-Bonding Using EBSD Measurement (EBSD측정에 의한 반복겹침접합압연된 무산소동의 두께방향으로의 미세조직 변화 분석)

  • Lee, Seong-Hee;Lim, Cha-Yong
    • Korean Journal of Materials Research
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    • v.24 no.11
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    • pp.585-590
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    • 2014
  • Microstructural evolution in the thickness direction of an oxygen free copper processed by accumulative rollbonding (ARB) is investigated by electron back scatter diffraction (EBSD) measurement. For the ARB, two copper alloy sheets 1 mm thick, 30 mm wide and 300 mm long are first degreased and wire-brushed for sound bonding. The sheets are then stacked and roll-bonded by about 50% reduction rolling without lubrication at an ambient temperature. The bonded sheet is then cut to the two pieces of the same dimensions and the same procedure was repeated on the sheets up to eight cycles. The specimen after 1 cycle showed inhomogeneous microstructure in the thickness direction so that the grains near the surface were finer than those near the center. This inhomogeneity decreased with an increasing number of ARB cycles, and the grain sizes of the specimens after 3 cycles were almost identical. In addition, the aspect ratio of the grains decreased with an increasing number of ARB cycles due to the subdivision of the grains by shear deformation. The fraction of grains with high angle grain boundaries also increased with continuing process of the ARB so that it was higher than that of the low angle grain boundaries in specimens after 3 cycles. A discontinuous dynamic recrystallization occurred partially in specimens after 5 cycles.

Adaptive Analysis of Multilayered Composite and Sandwich Plates (적층복합재료 및 샌드위치 판의 적응해석)

  • 박진우;김용협
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2001.05a
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    • pp.224-227
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    • 2001
  • Adaptive analysis of multilayered composite and sandwich plates is carried out. The adaptive analysis is based on a finite element error form, which measures the difference between the through-the-thickness distribution of finite element displacement and the actual displacement. The region where the error-measure exceeds the prescribed admitted error value, the finite element mesh locally refined in the thickness direction using the mesh superposition technique. Several numerical tests are conducted to validate the effectiveness of the current approach for adaptive analysis of laminated plates.

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Effect of non-metallic inclusion on susceptibility to lamellar tearing (라멜라 테어 발생감수성에 미치는 비금속개재물의 영향)

  • 방국수;이종봉
    • Journal of Welding and Joining
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    • v.3 no.1
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    • pp.3-10
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    • 1985
  • Lamellar tearing susceptibility and through-thickness tensile ductility have been investigated in $40kg/mm^2 and 50kg/mm^2$ class tensile strength steel plates in terms of cleanliness of non-metallic inclusion and welding condition. The plate which had 0.01% cleanliness of A-type inclusion (MnS) had 61% of the reduction of area in the through-thickness direction and did not show lamellar tearing. Lamellar tearing susceptibility decreased with increasing the preheat and interpass temperature. The plate which had 0.04% cleanliness of A-type inclusion did not show lamellar tearing under the condition of 75.deg. C of preheat and interpass temperature.

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Investigation of Deep Drawability and Product Qualities of Ultra Thin Beryllium Copper Sheet Metal (베릴륨동 극박판의 드로잉 성형성과 품질특성 연구)

  • Park, S.S.;Hwang, K.B.;Kim, J.B.;Kim, J.H.
    • Transactions of Materials Processing
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    • v.19 no.3
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    • pp.179-184
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    • 2010
  • The present study is focused on the deep drawability and product qualities of ultra thin beryllium copper sheet metal. The goal of this research is to investigate the limit drawing ratio in deep drawing of ultra thin beryllium copper metal. For the experiment, beryllium copper(C1720, $50{\mu}m$ in thickness) is used. Tensile test are also carried out to find out the material properties. Deep drawing experiments are carried out in Universal Testing Machine(UTM) to obtain limit drawing ratio. Deep drawing tests are carried out for various specimen sizes. Teflon film is used as a lubricant and constant blank holding force is imposed. Sheet thickness and surface hardness are measured along radial direction after deep drawing. Thickness is measured using optical microscope. For beryllium copper(C1720), the maximum LDR of 2.4 is obtained when the die shoulder radius is 20 or 30 times of sheet thickness.

Controllability of Threshold Voltage of ZnO Nanowire Field Effect Transistors by Manipulating Nanowire Diameter by Varying the Catalyst Thickness

  • Lee, Sang Yeol
    • Transactions on Electrical and Electronic Materials
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    • v.14 no.3
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    • pp.156-159
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    • 2013
  • The electrical properties of ZnO nanowire field effect transistors (FETs) have been investigated depending on various diameters of nanowires. The ZnO nanowires were synthesized with an Au catalyst on c-plane $Al_2O_3$ substrates using hot-walled pulsed laser deposition (HW-PLD). The nanowire FETs are fabricated by conventional photo-lithography. The diameter of ZnO nanowires is simply controlled by changing the thickness of the Au catalyst metal, which is confirmed by FE-SEM. It has been clearly observed that the ZnO nanowires showed different diameters simply depending on the thickness of the Au catalyst. As the diameter of ZnO nanowires increased, the threshold voltage of ZnO nanowires shifted to the negative direction systematically. The results are attributed to the difference of conductive layer in the nanowires with different diameters of nanowires, which is simply controlled by changing the catalyst thickness. The results show the possibility for the simple method of the fabrication of nanowire logic circuits using enhanced and depleted mode.

Analysis of the Thickness Effect for Hysteresis Ring of Hysteresis Motor with Vector Hysteresis Model

  • Hong, Sun-Ki
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.20 no.9
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    • pp.84-89
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    • 2006
  • This paper presents the thickness effect of hysteresis ring of hysteresis motor using finite element method combined with a vector hysteresis model. From the magnitude and direction of the magnetic field intensity, the magnetization of each ring element is calculated by a vector hysteresis model. The developed torque can be obtained with the vector sum of individual torque of each element on the hysteresis ring. From these calculations, it can be found that the motor torque is not in proportion to the thickness of the ring. As a result, there exists a proper point of thickness and that can be determined using the proposed methoㅇ in this paper.

Drape property of fabrics and Shape horizontal section of hem line of flare skirt (직물의 Drape 특성과 Flare Skirt의 헴라인 단면 형상)

  • 이수정
    • Journal of the Korean Home Economics Association
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    • v.33 no.4
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    • pp.149-155
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    • 1995
  • In this study, the formative property of flare skirts is carry out by the shape horizontal sections of hem line. Flare skirts was made by 10 kinds of fabrics with different physical properties. the length of flare skirts was 60cm. The main results obtained are as follows ; 1, The shape horizontal sections of hem line has differed with number of nodes and fabrics properties, in direction of texture. 2. According to the fabrics analysis of drapability decreased in order from Polyester/nylon(20/80)>Polyester(twill, thickness 0.2441)>Polyester(plain, thickness0.3760)>Polyester(plain, thickness 0.3687)>Polyester(plain, thickness 0.3101). 3. The correlation between the number of nodes and wave-height of modes and breadth showed a high negative correlation with the drapability of fabrics.

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A Study on the Superplastic Sheet Forming by the FEM and Experiment (초소성 판재 성형을 위한 유한요소 해석 및 실험에 관한 연구)

  • Lee, Seung-Jun;Lee, Jung-Hwan;Lee, Young-Seon
    • Proceedings of the KSME Conference
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    • 2000.04a
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    • pp.866-872
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    • 2000
  • Superplastic forming processes by characteristic of low flow stress and high elongation have advantages to reducing on production cost and weight because of the product of complex form could be made in one part. However superplastically termed part has a characteristic of non-uniform thickness distribution along forming direction. Especially. since the thickness distribution affects on mechanical properties of product. the uniform thickness is very important. There are two solution procedure of implicit and explicit procedure to analyze the superplastic forming. In this study to analyze the thickness distribution two kinds of commercial programs of DEFORM and PAM-STAMP which implicit and explicit code are used respectly. The results from the two Programs were compared with eath other As a result implicit code were more suitable than explicit code for superplastic forming analysis.

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Optimal Design of Filament Wound Composite CNG Pressure Vessel (필라멘트 와인딩 복합재 CNG 압력용기의 최적설계)

  • Yun, Yeong-Bok;Jo, Seong-Won;Ha, Seong-Gyu
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.26 no.1
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    • pp.23-30
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    • 2002
  • Abstract The optimization is performed to reduce the mass of CNG pressure vessel reinforced with composite materials in the hoop direction. An axisymmetric shell element which takes into account the layered liner and hoop composite materials is thus developed and incorporated into a program Axicom. The accuracy of the program is then verified using the 4 noded element in ANSYS. Three different cases of optimization are then performed using the Axicom: (1) uniform hoop thickness, (2) varying hoop thickness, and (3) varying the ply angles and accordingly the thickness. Compared with a traditional method, cases (2) and (3) were found to be very effective in reducing the thickness and cost of the hoop composite materials by about 80% without sacrificing the safety factors.