• Title/Summary/Keyword: drawing method

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Effect of Uniaxial Drawing Conditions on the Orientation of Poly (ethylene 2,6- naphthalate) (일축 연신 조건에 따른 Poly(ethylene 2,6-naphthalate) 배향에 관한 연구)

  • 진병석;이성효;이광희
    • Polymer(Korea)
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    • v.25 no.5
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    • pp.699-706
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    • 2001
  • The effects of uniaxial drawing conditions on the molecular orientation of poly (ethylene 2,6-naphthalate) (PEN) are investigated. Birefringence measurements show that the orientation is significantly enhanced at high draw ratio, low drawing temperature, and fast drawing speed. The characteristics of orientation examined by FTIR- ATR dichroism method represent almost same results. Amorphous orientation function increases with drawing rate at $120^{\circ}C$, but it decreases with drawing rate at $141^{\circ}C$. These behaviors can be explained with the relation between crystallization and chain relaxation rates. It is observed that the orientation of PEN film is accompanied by significant alignment of the naphthalene rings of PEN parallel to the film surface.

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Formability of Sheet Metal in Noncircular Cup Drawing(I) (for Rectangular Cross Section) (비원형 단면에 대한 판재 성형성(I) (직사각형 단면에 대하여))

  • Shin, J.H.;Kim, M.S.;Seo, D.K.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.2 no.1
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    • pp.84-95
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    • 1994
  • The effects of punch and blank shapes in the rectangular cup drawing process are examined experimentally to improve the formabilities. For this purpose, three blank shapes which are h-bl., G-bl., and T-bl., and five punch shape factors which are the ratios of two adjacent side lengths in rectangular cross section are adopted. The constructing methods of the three blank shapes are as follows. The h-bl. is designed by slip-line theory, and the G-bl. is selected for the similar shape to the punch. The T-bl. is obtained by the drawing method which is introduced in the technical references. The five punch shape factors are selected for length/width=1, 1.25, 1.5, 1.75 and 2. The experimental procedures are performed for all the above forming conditions to investigate and compare the formabilities. As a result, it is verified experimentally that the rectangular cups drawn by the h-bl. are more ideal than those drawn by G-bl. and T-bl.. They have not only higher limiting drawing ratio, more uniformity in drawn cup heights and more ideal thickness distributions, but also need relatively less maximum drawing forces.

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Pass Schedule Design for Improvement of Drawing Speed in the Dry Wire Drawing Process (신선 속도 향상을 위한 건식 신선 공정의 패스스케줄 설계)

  • 김영식;김동환;김병민;김민안;박용민
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.11a
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    • pp.600-603
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    • 2000
  • In the high carbon steel wire drawing process, the wire temperature increases as the drawing speed is faster in order to increase the production rate in the shop floor. The rapid temperature rise causes the wire fracture in the dry wire drawing process. So, in this paper, the isothermal pass schedule program, which includes the calculation method of wire temperature at each pass, is proposed to prevent the wire fracture due to the temperature rise. Using the isothermal pass schedule program, it is newly proposed the pass schedule design system that prevents the cup-cone defects, improves the elongation of the final products and assures further deformation. As a result, the temperature rise of the wire was decreased and the production rate of the final product is remarkably grown up according to the increase of the final drawing speed than that of the conventional process. Also, the proposed pass schedule design system could give a useful information to the process designer who would design the high carbon steel wire drawing process.

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Elastic-Plastic Finite Element Analysis of Deep Drawings of Circular and Square Cups Considering Bending (굽힘을 고려한 원형 및 정사각형컵 딥드로잉 공정의 탄소성 유한요소해석)

  • 심현보;양동열
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.7
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    • pp.1738-1750
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    • 1994
  • Both cylindrical cup drawing and square cup drawing are analyzed using membrane analysis as well as shell analysis by the elastic-plastic finite element method. An incremental formulation incorporating the effect of large deformation and normal anisotropy is used for the analysis of elastic-plastic non-steady deformation. The computed results are compared with the existing experimental results to show the validity of the analysis. Comparisons are made in the punch load and distribution of thickness strain between the membrane analysis and the shell analysis for both cylindrical and square cup drawing processes. In punch load, both analyses show very little difference and also show generally good agreement with the experiment. For the cylindrical cup deep drawing, the computed thickness strain of a membrane analysis, however, shows a wide difference with the experiment. In the shell analysis, the thickness strain shows good agrement with the experiment. For the square cup deep drawing, both membrane and shell analyses show a wide difference with experiment, this may be attributable to the ignorance of the shear deformation. Concludingly, it has been shown that the membrane approach shows a limitation for the deep drawing process in which the effect of bending is not negligible and more exact information on the thickness strain distribution is required.

The Digital Drawing Production Using Digital Camera (디지털 카메라를 이용한 수치도면작성)

  • Choi, Seung-Pil;Park, Jong-Sun;Choi, Chul-Soon
    • Journal of Korean Society for Geospatial Information Science
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    • v.12 no.3 s.30
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    • pp.91-97
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    • 2004
  • As for the former analogue method of photogrammetry, We have obtained final digital drawing by creating the stereo model from overlapped images through orientation process using plotting instrument and processing restitution procedure. However, digital photogrammetry batch processes such using small computer system thus We make an attempt automatization of the procedures. And without the production of stereo model, We could obtain 3D digital data through analysis method. Therefore, an objective of this study was to implement a surveying system that could 3D surveying positions using the digital image to reduce limitations of control point surveying and photographing conditions more efficiently to produce digital drawing. By the result, photogrammetry can practice and make out digital drawing to a computer by digital camera of a comparative low-cost. Small scale area can become practical use to drawing production etc. for facilities management because area can make out digital drawing economically than general surveying.

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The Influences of Situational Interest, Attention, and Cognitive Effort on Drawing as a Method to Assist Students to Connect and Integrate Multiple External Representations (외적 표상들 간의 연계와 통합을 촉진하는 방안으로서의 그리기에 미치는 상황 흥미, 주의집중, 인지적 노력의 영향)

  • Kang, Hun-Sik;Noh, Tae-Hee
    • Journal of The Korean Association For Science Education
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    • v.26 no.4
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    • pp.510-517
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    • 2006
  • This study investigated the influences of situational interest, attention, and cognitive effort on drawing as a method to assist students to connect and integrate multiple external representations provided in learning chemical concepts. Seventh graders (N=178) at two coed middle schools were taught about the "Boyle's Law" and the "Charles's Law" for two class hours through drawing. They observed macroscopic phenomena through demonstrations. After these observations, they drew their mental model from the external verbal representation, and then compared their drawings with external visual representation. The tests assessing situational interest, attention, cognitive effort, and conceptual understanding were administered as post-tests. Correlation and path analyses supported a causal model which situational interest had a positive direct effect on attention to the drawing. Attention led to conceptual understanding directly as well as through cognitive effort. These results suggest that situational interest may be induced by drawing first of all, and attention and cognitive effort may be direct causes of conceptual understanding in drawing. Educational implications are discussed.

A Study on Multi-stage Deep Drawing Processes Using Finite Element Method (유한요소법을 이용한 다단계 디프 드로잉 공정에 관한 연구)

  • 최병화;민동균;박태종
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2002.05a
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    • pp.1021-1025
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    • 2002
  • There have been many researches performed on the formability of axisymmetric or rectangular cup shapes in the deep drawing processes. But non-axisymmetric deep drawing processes rely upon empirical knowledge of experts in most cases. Especially, there have been few researches for multi-stage elliptical deep drawing processes. In this study, formability and thickness distributions of elliptical yoke products were predicted by using finite element analysis. The results of the analysis were compared with those of experiments for validity.

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Finite Element Analysis of Damage Evolution in Drawing of Hardening Viscoplastic Metals (변형경화성을 갖는 점소성재의 인발공정에서 결함성장의 유한요소해석)

  • 함승연;이용신
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1994.03a
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    • pp.71-79
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    • 1994
  • Strip drawing of strain-hardening, viscoplastic materials with damage is analyzed by a rigid plastic finite element method. A process model is formulated using two state variables, one for strain hardening from slip dominated plastic distortion and the other for damage from growth of microvoids. Application of the model to steady state drawing is given via implementation in a consistent penalty finite element formulation. The predicted density changes as a result of void growth are compared to those from experiments reported in the literature. The effects of drawing conditions such as drawing speed and die angle on the mechanical property changes are studied.

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Kinetic Family Drawing According to Preschoolers' External Problem Behavior (유아의 외현화 문제행동 여부에 따른 동적가족화 연구)

  • Kim, Jin-Kyung
    • Journal of Families and Better Life
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    • v.31 no.1
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    • pp.61-72
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    • 2013
  • This study evaluated Kinetic Family Drawing according to preschoolers' external problem behavior. To achieve this, 120 preschoolers who were four or five years old were investigated and data were statistically analyzed using mean, and chi square analysis with the SPSS Win 13.0 program. The preschoolers' family drawings were analyzed by using the method in Kinetic Family Drawing(Burns & Kaufman, 1972). First, regarding characteristics, the preschoolers in the aggression group rotated certain person or drew the figure from behind, the preschoolers in the delinquency group drew long arms, the figure from behind, and angular forms. Second, regarding action depicted, the preschoolers in both aggression and delinquency groups perceived the lower activity level of their fathers, dangerous situations, and excluded family interaction. Third, regarding symbols, the preschoolers in the delinquency group drew objects such as balls. Finally, regarding drawing style, the preschoolers in the delinquency group drew edges and underline.

The Study for Middle School Students' Environmental Awareness with Drawing Activity about Environment (환경그리기를 통한 중학생의 환경인식 조사)

  • Kim, Myung-Gyun;Cheong, Cheol
    • Journal of Environmental Science International
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    • v.16 no.4
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    • pp.479-485
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    • 2007
  • This study investigated the environmental awareness synthetically with the drawing activity for making up for the weak points in the writing test that cannot measure emotional aspects. This study found that students have negative viewpoints on reasonable judgement for the present and future environment of the earth, while they show hope to live in better environment in their mind. Furthermore, it found that the drawing activity can be adopted as a complement for the traditional measuring method of the environmental awareness, through which this middle school students' sensibility to the environment can be shown. It also inferred that the drawing activity can be used as a way of education during school classes for environment and it can increase the sensibility to the environment in mind.