• The Journal of Society for e-Business Studies
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• v.1 no.2
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• pp.77-92
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• 1996

In recent years, the manufacturing industry begins to demand the PDM which integarates design and manufacturing information concurrently to reduce the time-to-market of new products. However, current commercialized PDM tools have drawbacks in representing by relational data modeling a variety of data types such as CAD files, images, audio, long text, etc. For this reason, object-oriented approaches are suggested as an alternative. In this paper, using one of object-oriented approaches, Rumbaugh's OMT(Object-Modeling Technique), we propose a data model of drawing information management systems essential for PDM. The scope of the model is limited to the information management for drawings, parts, and product structures. Static, dynamic and functional models are suggested in detail. In the models, the drawing status is classified into on-progress, approved, disposed, and released. Also, parts are classified into products, assemblies, and components.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.7
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• pp.24-31
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• 1999

Bulging is a forming method to shape of die cavity by using hydraulic pressure in tube or vessel. Bulging machine and die were developed in order to produce vessel for keeping warm. Bulging machine is a double type with two horizontal cylinders for bulging of two pieces at the same time. The developed die system has one bulging die and two drawing dies for necking at the both ends of tube. The diameter of tube expands by hydraulic pressure in tube. at the same time, thrust at the both ends of tube. pushes tube in the direction of expansion to obtain high expanding rate with no crack. In this study, the bulging properties were investigated to solve tube crack and necking in manufacturing vessel by the combination method of bulging and drawing. As a result, high expanding rate of tube radius without crack, precision necking and high productivity were obtained.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.3 no.1
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• pp.52-58
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• 2004

The material used is a commercial magnesium based alloy AZ31(Mg-3Al-1Zn)sheet with a thickness of 1.0mm. Uniaxial tension tests at warm temperature were carried out to investigate the material characteristics of K, m, and n. A warm drawing process with a local heating and cooling technique was developed to improve formability in this study with results of uniaxial tension tests because it is very difficult for Mg alloy to deform at room temperature by the conventional method. The die and blank holder were heated up, while the punch was water-cooled during deformation. FE simulations considering heat transfer were executed with Mg alloy to investigate the Improvement of deep drawability. For the assessment of improvement those were compare with the results of no considering heat transfer and room temperature.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.18 no.9
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• pp.100-105
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• 2019

In wire drawing, aterial deformation is concentrated on the surface of the drawn wire because of surface contact with the drawing die. Therefore, strain varies from the center to the surface of the drawn wire. In this study, based on the upper bound method, an effective strain prediction method from the center to the surface of a drawn wire was proposed. Using the proposed method, the effective strain of the drawn wire was calculated verify the proposed prediction method, the predicted effective strain was compared with the result of finite element analysis.

• 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.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1991.11a
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• pp.95-100
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• 1991

From a manufacturing standpoint it would be desirable to monitor the degradation of drawing die, that is essential for the maintenance of quality, the evaluation of product integrity and the reducing scrap. Acoustic emission is powerful method in monitoring fine wire drawing process, especially in detecting the die fracture at early stage. Experiments at so suggested that acoustic emission signals contained valuable information regarding the stage of a drawing process such as the surface appearance of products and the condition of lubrication. Using these informations makes AE monitoring techniques a possible tool in monitoring the drawing process operation. In order to approach this, this paper discusses the nature of acoustic emission signals produced in drawing process under various conditions. Experimental results are presented which illustrate the effects of wire and die material, lubricants, and drawing speed on the generation and the mean voltage level of acoustic emission signals. The results from these tests give controlling factors of acoustic emission generation.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.10a
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• pp.166-171
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• 2001

Copper bus-bar is made by drawing process and used in many part of industry. When design drawing die for copper bus-bar, design factor is focused on the deformation of die-land by drawing force and shrink fit. In this paper, to determine shrink fit value is analyzed by automatic shrink fit analysis program, APDL/UIDL language in a commercial FEM package, ANSYS, has been developed that enables optimal design of the dies taking into account the elastic deflections generated in shrink fitting the die inserts and that caused by the stresses generated in the process and by using DEFORM software for drawing process analysis. This data can be processed as load input data for a finite element die-stress analysis. Process simulation and stress analysis are thus combined during the drawing die design. The stress analysis of the dies is used to determine optimized dimension of die-land.

• International Journal of Precision Engineering and Manufacturing
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• v.4 no.1
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• pp.5-8
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• 2003

The rectangular deep drawing process is widely used in sheet metal forming, but there are various associated defects, such as earing, wrinkling, tearing, etc. In order to avoid such defects, an optimum blank shape is required. Such an optimum blank shape cannot be generalized because deep drawing processes are involved in complex process parameters. So, it is necessary to do systematic research to determine the optimum blank shape for the deep drawing process. In this study, a rectangular cup drawing test has been carried out to determine the optimum blank shape for various stainless steel sheets. From the test, a new blank model, which has no earing, is propsed.

• Transactions of Materials Processing
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• v.10 no.6
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• pp.456-464
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• 2001

Deep drawing and ironing are tile major process today in manufacturing of aluminum alloy battery case used in cellular phone. Most of these process require multi-stage ironing following the deep drawing and redrawing processes. The practical aspects of this technology are well known and gained through extensive experiment and production know-how. However, the fundamental aspects of these processes are relatively less known. Thus, it is expected that process analysis using FEM techniques would provide additional detailed information that could be utilized to improve the process condition. This paper illustrates the application of process modeling to deep drawing and redrawing operations. To verify the simulation results, the experimental investigations were also carried out on a real industrial product. The numerical analysis by FEM shows good agreement with the experimental results in view of the deformation shape of the product. A commercially available finite element code LS-DYNA3D was used to simulate deep drawing and redrawing operations.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.10a
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• pp.406-411
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• 2003

It is clearly demonstrated that deeper cups could be formed by single and double stretch-drawings from smaller circular blanks due to such wall-thinning action than in the usual deep-drawing of larger blanks. From this fact, it is emphasized that the deep-drawability of a sheet metal Is not evaluated simply by the conventional L.D.R (limiting drawing ratio), but the depth of the drawn cup should also be taken into account. Many experimental data about various metals and thicknesses given in this paper offer a valuable information in this process for more general use which recommends to replace the conventional deep-drawing process by the stretch-drawing process both for single and double operations. In the single stretch-drawing, it is also confirmed that a deeper cup can be produced by raising the blank-holding force at later stage of operation.