• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2000.04a
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• pp.92-95
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• 2000

In order to obtain the optimal products in deep drawing process elliptical deep drawing tests were carried out with several shape radii of the punch and die. As parameters on testing shape radii of the punch and die were selected, In addition the conventional shape radii have been determined by trial=and-error using industrial experience and post processing test and only approximate shape radii of the punch and die have been presented. The optimal shape radii of the punch and die in elliptical deep drawing process with biaxisymmetric blank shape are proposed. In this study we suggest the appropriate conditions to be applicable to the catual manufacturing processes through the experiment and finite element method.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2000.04a
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• pp.146-150
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• 2000

there are a lot of process variable exerted influence on the formability of products in deep drawing process. Particularly it is important that blank shape of the process variables. A paper to be connected with process variables of elliptical deep drawing products is insufficient the actual circumstances enough though researches have been performed on the deep drawing of sheet metal forming. In this study The effects of thickness distribution and movement of sheet are grasped as alteration of blank shapes in the process of elliptical deep drawing product and then optimal blank shape was presented. They were verified by the finite element analysis (FEA) and experiment.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2004.10a
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• pp.175-179
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• 2004

Since the formability of AZ31 magnesium alloy is not good in room temperature, it is known that high temperature forming is advantageous. However, many studies are necessary to find the proper forming temperature for Mg alloy. In this study, experimental and FEM analysis are performed to investigate the forming temperature for AZ31 sheet. The deep drawing process of square cup is used in forming experiment and FEA. The investigations are performed in three forming temperature, room temperature, $250^{\circ}C\;and\;400^{\circ}C$. The square cup is well formed in $250^{\circ}C$ forming temperature, on the other hand, the crack and failure is presented in corner section in room and $250^{\circ}C$ forming temperature. The main cause is investigated as the effect of hardening range by the experimental and FEM results.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.8
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• pp.59-70
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• 1999

This paper deals with automated computer-aided process planning by which designers can determine operation sequences even if they have little experience in the design of press working products. The computer-aided process planning in hot forging, deep drawing and blanking requires many kinds of technical and empirical skills based on investigation and collection of the knowledge of their processes. An approach to the CAPP system is based on the knowledge-based rules and the process knowledge base consisting of process planning rules is built. The methodology adopted to develop the system is elaborated in this paper. This system has been written in AutoLISP on the AutoCAD with a personal computer and provides powerful capabilities for process planning of hot forging, cold forging, deep drawing and blanking products.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.8
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• pp.88-95
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• 1996

유리섬유가 강화된 열가소성 복합재료 판재의 성형성에 대한 이해를 돕기 위해 이론적 고찰과 실험적 고찰이 행해졌다. 성형시험에서 사용된 형상은 임의의 방향으로 위치한 유리섬유를 중량비로 30% 함유한 폴리프로필렌 재료가 사용되었고, 시험된 형상은 판재의 굽힘성이나 인장성을 측정하는데 널리 사용되는 스위프트컵(Swift flat-bottomed cup)모양이다. 성형시험과 재료시험은 플리프로필렌 Matrix의 유리성 천이온도(Glass transition temperature)와 용융온도 사이에서 행해졌다. 본 연구의 이론과 고찰을 위해서 재료의 평면 방향으로는 동질성을 그리고 그 직각 방향으로는 이질성을 가진 연속체 물질로 가정하여 유도하였다. 이러한 이론적 결과는 실험 결과와 비교되어졌고,이를 통해 시험된 재료의 최적의 성형조건을 제시하였다.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.235-238
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• 2005

In this study, it is investigated that the effect of material properties such as strength coefficient and strain hardening exponent on formability of AZ31 alloy sheet in square cup deep drawing process. Mechanical properties of AZ31 alloy sheet at elevated temperature $250^{\circ}C$ are obtained from uniaxial tensile tests and based on these results, a series of square cup deep drawing tests at the same temperature condition are carried out. Also, the possibilities of necking initiation is predicted by the FEM and FLD and compared with experimental results.

• Transactions of Materials Processing
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• v.8 no.6
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• pp.591-603
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• 1999

A computer-aided process planning system for rotationally symmetric deep drawing products has been developed. The application for non-axisymmetric components, however, has been reported yet. Therefore, this study investigates process sequence design in deep drawing process and constructs a computer-aided process planning system for non-axisymmetric motor frame products with elliptical shape. The system developed consists of three modules. The first one os a 3-dimensional modeling module to calculate surface area for non-axisymmetric products. The second one is a blank design module that creates an oval-shaped blank with the identical surface area. The third one is a process planning module based on production rules that play the best important roles in an expert system for manufacturing. The production rules are generated and upgraded by interviewing with field engineers. Especially, drawing coefficient, punch and die radii are considered as main design parameters. The constructed system for elliptical deep drawing products would be very useful to reduce lead time and improve accuracy for production.

• Transactions of Materials Processing
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• v.9 no.2
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• pp.120-127
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• 2000

Recently, most of researches for sheet metal deep drawing process have been performed on the formability of axisymmetric shape, but there are not any concrete reports on the formability of non-axisymmetric shape. In addition, the conventional shape radius of the punch and die has been determined by trial-and-error using industrial experience and post processing test, and only approximate shape radius of the punch and die has been presented. In this study, the optimal shape radius of the punch and die in deep drawing process with biaxisymmetric blank shape is proposed. Through the deep drawing experiment, especially it is found that in order to obtain the optimal products, and improvement of formability can be researched by selection of such punch and die shape radius that gives an adequate thickness distribution in all processes.

• Transactions of Materials Processing
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• v.9 no.6
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• pp.638-643
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• 2000

This study Is concerned with the development of design support program for deep drawing process. The present support program is designed to generate the layout drawings by utilizing the following key functions: analysis of product shape, generation of key stages by pattern database, determination of layout generation method, generation of layout. furthermore, from the results by process design program input data for simulation Is automatically generated with appropriate process parameters and connected seamlessly to carry out the finite element analysis so that the design can be checked for the possible problems in real manufacturing process. The designer can generate layout drawings and test the design by simulation quickly and conveniently In these system designer can verify and optimize the design. We tested this system for various type of product shape md found that the generated layout is in good agreement with the real cases.

• Transactions of Materials Processing
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• v.5 no.1
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• pp.61-71
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• 1996

A computer-aided process design system for axisymmetric deep drawing products has been developed. An approach to the system is based on the knowledge based system. Knowledges for the system are formulated from the plasticity theory handbooks experimental results and empirical knowhow of the field experts. the system is composed of four main modules such as geometrical design test & rectification and user modification. The input to the system is final sheet-metal object geometry and the output from the system is process sequence with intermedi-ate objects geometries and process parameters, such as drawing load blank holding force clearance cup-drawing coefficient.