• Transactions of Materials Processing
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• v.20 no.5
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• pp.357-361
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• 2011

A beryllium copper alloy(C1720) sheet was stretch-drawn using different processes. A hemispherical punch was first used and the forming behavior was examined. Then, cylindrical cups with a hemispherical head were produced by either one-step drawing or two-step forming(sequential stretch forming-drawing). The one-step drawing showed the better formability than two-step forming. However, the two-step forming was the superior process in terms of attaining shape accuracy.

• Journal of the Korean institute of surface engineering
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• v.36 no.4
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• pp.339-346
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• 2003

Stainless steel wire has been used in industry, dental and medical parts. Especially, it has been used widely for the dental orthodontic materials. The orthodontic wire requires good mechanical properties, such as elastic strength, combined with a high resistance to corrosion. To increase elastic strength and good corrosion resistance, drawing methods(one-step and two-step drawing) have been used and the electrochemical characteristics of drawed wire have been researched using potentiodynamic method in 0.9％NaCl and field emission scanning electron microscope. The one-step drawed wire showed the formation of rough surface. The hardness and tensile strength of two-step drawed wire increased. For the case of two-step drawed wire, the corrosion resistance and pitting potential increased compared with one-step drawed wire due to the drawing induced small surface roughness, such as scratch. The passivation and active current density decreased as the reduction in area for drawing increased.

• Cartoon and Animation Studies
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• s.9
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• pp.250-265
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• 2005

Life drawing is one of the most important curriculum not only in 2D animation but also in 3D animation. It was secret weapon of Disney how they made great success of Snow White and Seven Dwarfs and all the fame of Disney animation. Life Drawing which has its back ground history is major curriculum of famous animation school such as CAL Arts which Disney made and Sheridan College in Canada. But in Korea, a lot of the universities and colleges which have animation department do not really seem to understand the importance of the life drawing and it's effectiveness, thus do not emphasize it as a short cut to get close to the real work field. Now that the academical society as well as industry are very well of the fact that the animation education is directly related to the animation industry, the schools should have to teach step by step and closer to the basic fundamentals. The intentions of this study is to emphasize the importance of the Life Drawing, one of the essential fundamental course, which not only help the universities and colleges that have animation course to organize their curriculum. but also to help the students who graduate the program easily find their position in the animation industry.

• Transactions of Materials Processing
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• v.25 no.6
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• pp.390-395
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• 2016

GDI fuel rail is component of GDI system which directly fuel with high pressure in the engine combustion chamber. And it is required to high strength and dimensional accuracy. Multi roll-die drawing process consists of the idle roll-die and drawing die in tandem. In the course of drawing with roll-die, deformation takes place between the idle roller pair or pairs. The friction force decreases with the idle roll-die, enabling the reductions to be risen in one step. In this study, the caliber of 4-roll was designed into pass schedule that made the draw force at the exit of the drawing die be equal. In order to compensate for over-filling area, the roll caliber was modified using the result of FE-analysis. The results of FE-analysis and experiment show that the proposed design method can be used to effectively design the multi roll-die process, leading to an accurate shape and correct dimensions of the final within an allowable tolerance of ${\pm}0.08mm$. Furthermore, the productivity was evaluated by comparing with multi roll-die drawing process and conventional multi shape drawing process. The result was confirmed that it has an efficiency of about 2 times than conventional process in terms of time.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.3
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• pp.198-204
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• 1993

The study is concerned with finite element analysis and design of axisymmetric deep drawing by local heating. When the bottom shape of a cup is not flat but in complex-shaped, i.e., hemispherical, the cup cannot be drawn in one or two processes in the conventional deep drawing process and the limit drawing ratio is limited as well. By introducing local heating selectively with regards to the heating position, the formability of the sheet metal can be greatly increased with the reduced number of processes. In the Process analysisthe rigid- viscoplastic finite element method is employed and the temperature effect is incorporated. Bishop's step-wise decoupled method is employed to analyze the thermomechanical interaction between deformation and heat transfer. Axisymmetric deep drawing of a hemisphere-bottomed cup has been analyzed for various combinations of heat application in the punch and the die. At the first stage of deep drawing stretch forming is practically carried out by firmly pressing the blankholder with the punch and the die heated at various levels of temperature. Then at the second stage the same cup is drawn for the saame or different combination of temperature. From the computation, it has thus been shown that the fromability of a cup is greatly increased in two-stage deep drawing with increased limet drawing ratio.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1997.03a
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• pp.179-182
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• 1997

One-step inverse methods based on deformation theory causes some amount of error. The amount of error is generally increased as the deformation path is more complex. As a remedy, a new three dimensional multi-step inverse method is introduced for optimum design of blank shapes and strain distributions from desired final shapes. The approach extends a one-step inverse method to a multi-step inverse method in order to reduce the amount of error. The algorithm developed is applied to square cup drawing to confirm its validity by demonstrating reasonably accurate numerical results.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.12
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• pp.2055-2067
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• 1997

Values of process parameters in sheet metal forming can be estimated by various one-step inverse methods. One-step inverse methods based on deformation theory, however, cause some amount of error. The amount of error is generally increased as the deformation path becomes more complex. As a remedy, a new three dimensional multi-step inverse method is introduced for optimum design of blank shapes and strain distributions from desired final shapes. The approach extends a one-step inverse method to a multi-step inverse method in order to reduce the amount of error. The algorithm developed is applied to square cup drawing to confirm its validity by demonstrating reasonably accurate numerical results. Rapid calculation with this algorithm enables easy determination of an initial blank of sheet metal forming.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.10a
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• pp.81-84
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• 2001

An inverse finite element approach is employed for more capability to design the optimum blank shape from the desired final shape with small amount of computation time and effort. In some drawing or stamping simulation with inverse method, it is difficult to apply inverse scheme due to the large aspect ratio or steep vertical angle of inclination. The reason is that initial guesses are hard to make out with present method for those cases. In this paper, a direct mesh marring scheme to generate initial guess on the sliding constraint surface described by finite element patches is suggested for one step inverse analysis to calculate initial blank shape. Radial type mapping is adopted for the simulation of rectangular cup drawing process with large aspect ratio and parallel type mapping for the simulation of S-Rail forming process with steep vertical angle of inclination.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1999.03b
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• pp.88-94
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• 1999

This study is to investigate the effects of warm deep drawing with steel sheets of SCP3C and SCP1 for improving deep drawability. Experiments were carried out in various working conditions such as forming temperature and lubricantion. The effect of lubricantion and temperature on drawabillity of steel sheets as well as thickness distribution of drawn oil pan were examined and discussed. One step forming at room temperature and uniform distribution of thickness was achieved at optimum formability for lubricantion. The optimum forming temperature was obtained that both the die and the blankholder were heated to 10$0^{\circ}C$ while the punch was cooled by circulating coolant of $0^{\circ}C$.

• Journal of the Korean Society of Fashion and Beauty
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• v.1 no.1 s.1
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• pp.65-78
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• 2003

This research is to provide practical help in learning hair and makeup illustration skills by presenting techniques for hair and makeup drawing; to serve efficient illustration education; and to enhance the status of beauty and contribute to artistic development. Hair style and makeup techniques include graphical one, pattern-centered one, one using pattern paper, simplifying one and mood one expressing image. Of them, this research made the illustrations to use cosmetics, color pencils and pastel based on the graphical technique. for each design of the illustrations, ethnic, sexy, natural, romantic and gorgeous images, which were considered to be appropriate to the graphical technique, were chosen by the researcher out of hair and makeup styles that appeared in the fashion magazines including Vogue, Gap, Mode et Mode from 2000 through 2001. In particular, they were chosen with focusing on basic styles. The summaries below were found with the experience of making illustrations. Various techniques and skills are required to express the ideas of hair and makeup styles. Of them, the graphical technique is very useful as the primary step to learn various techniques and improve drawing skills. First, the graphical technique may enable not only expressing what is desired to draw as is, but also accurately representing hair and makeup designs so as to convey objective expression. In this regard, it is a proper way to achieve its inherent purpose as conveyance of messages. Second, more accurate styling of hair and makeup is available through graphical expression, which helps understand related practical techniques. In addition, makeup illustration, which is expressed through direct makeup products and instruments, may serve skill improvement since such direct use provides the feeling of real makeup. Third, the graphical technique as a basic drawing skill may unrestrictedly show the artist's expression ability. Fourth, although artistic merits implying individuality and creativity should be shared through illustrations that express the artist's ideas or emotions, the graphical technique is the easiest method to beginners who just started learning of illustration, in that it enables expression without highly advanced skills.