• Journal of the Korean Society for Precision Engineering
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• v.19 no.2
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• pp.177-186
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• 2002

This paper describes a research work on the development of computer-aided design system far the deep drawing & ironing of high pressure gas cylinder. An approach to the design system is based on the knowledge-based rules. Knowledge for the system is formulated from plasticity theories, handbook, experimental results and the empirical knowledge of field experts. This system has been written in AutoLISP on the AutoCAD Rl4.0 using personal computer. This system is composed of three modules which are input. process design and drawing.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.5
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• pp.654-661
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• 2004

In deep drawing of sheet metal, there are many cases in which the uniform and thin wall thickness of the drawn products is more important than the bottom thickness. In this case, we can not easily get the deep drawn products with the uniform and precise wall thickness by only drawing process. Therefore in general the manufacturing processes which both the drawing and the ironing process are proceeded sequentially are used. But this method has the disadvantages of a cost-up, decrease of productivity and degradation of quality, because the ironing process is added after the drawing process. In this study, in order to improve those problems and to enhance the effect of deep drawing, the combined process of redrawing and ironing fur multistep drawing of cylindrical cups is used. In this experiment, we considered the characteristics of the combined process such as the relation between the drawing and ironing rates, the drawing limits and the forces needed for operations. The suggested force prediction shows that it can successfully represent experimental results.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.8
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• pp.21-29
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• 2003

This paper describes a research work on the development of computer-aided design system for deep drawing & ironing of a high pressure vessel. An approach to the system is based on the knowledge-based rules. Knowledge for the system is formulated from plasticity theories, handbook, experimental results and empirical knowledge of field experts. An attempt is made to link programs incorporating a number of expert design rules with the process variables obtained by commercial FEM software, DEFORM and ANSYS, to form a useful package. It is composed of five main modules, which are calculation of product thickness, input, production feasibility check, process planning, and autofrettage process modules and two submodules, which are folding check and process variable verification submodules. Programs for the system have been written in AutoLISP on the AutoCAD 2000 using personal computer. The developed system makes it possible to design and manufacture large high pressure vessel requiring D.D.I. process more efficiently.

• Journal of the Korean Society for Precision Engineering
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• v.30 no.6
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• pp.629-637
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• 2013

In this study, a theoretical analysis method was suggested for predicting forming loads of continuous deep drawing and ironing processes (D.D.I. processes) by considering back tension and continuity equation, and FEA for D.D.I. processes was performed. Dimensions of a punch and a mold on the basis of design rules for a CNG storage vessel were applied for the analysis. To verify the suggested theoretical analysis, the results of theoretical analysis were compared with both those of FEA and experiments of previous studies. As the result of analysis, the values and tendencies of the loads predicted by the theoretical analysis were in agreement with those of FEA and the experiments. So, it is considered that the analysis suggested has reliability for predicting the forming loads of the continuous processes(deep drawing+ironing(1)+ironing(2)).