• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1995년도 추계학술대회논문집
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• pp.128-135
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• 1995

Theoretical and experimental drawing characteristics for the step drawbead are discussed. The drawbead restraining forces and strains by the varous drawing angles are measured experimentally. Also, during the blank holding process, the strain distributions of upper and lower skins of specimens are analysed by the 2-D rigid-plastic F.E.M And the drawbead restraining forces and strain distributions for the drawn specimens by the drawing length are obtained by experiment.

• 한국조경학회지
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• 제28권6호
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• pp.16-28
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• 2001

The purpose of this study is to arrange the terminology of the drawings in Chosun Dynasty, and to investigate the characteristics of drawings after the middle of Chos n Dynasty. This study is based on the and analysis of historic documents and drawings including drawings from China and Japan. In order to accomplish this, the drawings for the process of design were studied first, and the techniques of drawing were studied next in comparison with Japanese drawing techniques. Lastly, the technicians of drawing were studied. The results of this study were as follows; 1) Though the procedures of design Choson dynasty were not divided into planning, designing, construction and maintenance just like those of modern society, a variety of drawings in that time were used in each level. 2) The drawings in Choson Dynasty ere divided into Tohyong and Tosol, and mostly, those for design and construction were Tohy ng. 3) Based on the interpretation of Japanese drawings, several suggestions were presented to solve the questions of the drawing techniques for design and construction. 4) The technicians of drawing were the painters who were trained in a government organization in charge of royal paintings. In the future, research of this area should be continued in to deepen study on drawings as historical materials. This research provides meaningful of guidance in the analysis of historic drawing paintings.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.942-945
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• 2005

Micron-sized metal wires are widely used in industries such as filtration, catalyst and composite materials, etc. In the wire drawing process, the die that is used conventionally is an effective and, at the same time, sensitive component. However, a typical array of the dies has caused many problems in the wire drawing process, e.g., large frictional force on the interface between wire and the resulting high heat generation, precise adjustment of the dies, extended cooling system, die abrasion, etc.. Because of these problems, there have been many works that are aiming at improving the efficiency of wire drawing process by analyzing the die geometry and by applying advanced die material to prolong the die life or even at developing a dieless wire drawing system. This paper is dealing with developing a new wire drawing system that is applicable to reduce the wire drawing steps with high draw ratio. The new wire drawing system does not use the dies, but use the self-induced heater that works on the basis of the resonant phenomenon of wire material. The electromagnetic wave is the heating source. The results of the study on the diameter reduction and microwave flow analysis show that the heating effectiveness of the wire is influenced by the energy distribution in the microwave propagation chamber. We can obtain diameter-reduced wires by using microwave in the dieless drawing process. Microwave as a heating source is capable of producing wires without applying dies in wire drawing process.

• 한국산업융합학회 논문집
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• 제27권3호
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• pp.573-580
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• 2024

Recently, the special alloy, for instance, such as Monel and Inconel, is used for valves, bolt/nuts, and fittings in semiconductor facility, FCEV(fuel cell electric vehicle) and hydrogen gas station, to reduce the hydrogen embrittlement. Even though the Monel material has high cost, it is recommended to use for the cases of ultra high pressure, ultra high leak-proof and so on. The purpose of this study is to investigate the characteristics of Monel material within elastic limit through the comparative analysis when Monel material is extruded or drawn. As the results, the deformation of Monel material was increased as the number of pass was increased, further, the deformation of Monel material by drawing was larger than that by extrusion. In the safety factor, the case that load is less than 420kN, the plastic deformation due to drawing could be happened faster than that due to extrusion. However, the case of more than 420kN, it showed that the plastic deformation for extrusion and drawing was almost similar.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2001년도 춘계학술대회 논문집
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• pp.85-88
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• 2001

Examination of the die design is carried out for a multi-stage rectangular cup drawing process with the large aspect ratio with the aid of the finite element analysis. The analysis considers the deep drawing process with the ironing process for the thickness control in the cup wall. Simulation is performed to investigate the deformation mechanism in the initial design and the modified design. The analysis clarifies that the irregular cross section and the irregular contact condition produces unfavorable deformation. The analysis results show that the modified design improves the quality of a deep-drawn product with the low possibility of failure. The analysis result also shows good agreement with the experimental one.

• 소성∙가공
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• 제3권1호
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• pp.120-132
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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 aluminum strip 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 chages are studied.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1999년도 추계학술대회논문집
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• pp.22-25
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• 1999

'There are a lot of process variables, exerted influence on the formability of products, in deep drawing process. Particularly, it is important that the punch and die shape radius of the process variables. Though researches have been performed on the deep drawing of sheet metal forming, like this study, but it is insufficient the actual circumstances that researches for process variables of the non-axisymmetric deep drawing products. In this study, An effect on thickness distribution is grasped as alteration of the punch and die shape radius in the process of non-axisyrnmetric deep drawing products, and then the optimal punch and die shape radius were presented, they were verified by the numerical analysis method (FEM).

• Journal of information and communication convergence engineering
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• 제6권1호
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• pp.6-9
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• 2008

In future domestic context aware applications the location of mobile devices is often required. Ultrasonic technology enables high resolution indoor position measurements. A disadvantage of state-of-art ultrasonic systems is that several base stations are required to estimate 3D position. This study aims to evaluate the efficiency and effectiveness of using UPS as a 3D free-hand writing or drawing tool. The processes include the design and testing of UPS as an efficient 3D free-hand writing or drawing tool in the air. The paper will further explain the system architecture of the UPS and how to use GPS as 3D free-hand writing or drawing tool. The efficiency and effectiveness of the system was confirmed by a computer software simulation. The software will further display the result of drawing or writing from the user by graphics. As a result, it is possible to implement UPS as a 3D free-hand writing or drawing tool in the air.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1998년도 제2회 박판성형심포지엄 논문집 박판성형기술의 현재와 미래
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• pp.74-82
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• 1998

The limit drawing ratio (LDR) is a major process parameter in the process design of deep drawing. If the actual drawing ratio is greater than the LDR for a particular stage, then an intermediate stage has to be added to the process sequence to avoid failure during the ratio. In this study, the optimal process design considering forming limit is performed for the first-drawing and redrawing by using finite element method combined with ductile fracture criterion. The LDR and the site of fracture initiation are predicted by means of the fracture criterion. From the results of finite element analysis, the optimal value of drawing ratio is obtained, which contributes to the more uniform distribution of thickness and the smaller values of the ductile fracture in final cup.

• 한국정밀공학회지
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• 제15권7호
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• pp.119-128
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• 1998

In this paper, nonsteady state shaped drawing process has been investigated using the three-dimensional rigid-plastic finite element method. In order to analyze the shaped drawing process, a method to define straight converging die considering straight die part, die radius part and bearing part has been proposed. In addition, the modeling of initial billet and the generation procedure of mesh system have been suggested. The three-dimensional rigid-plastic finite element simulation has been performed for a square sectional drawing process and its result has been confirmed in comparison with the existing experimental one. Also, for the same process conditions, the effect of perimeter ratio in the shaped drawing process has been investigated.