• Transactions of Materials Processing
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• v.4 no.3
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• pp.222-232
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• 1995

The planar anisotripic FEM analysis for predicting earing profiles and draw-in amounts in the deep-drawing process is introduced. An implicit, incremental, updated Lagrangian formulation with a rigid-viscoplastic constitutive equation is employed. Contact and friction are considered through the mesh-based unit vector and normal contact pressure. The consistent full set of governing relations, which is comprising euilbrium and geometric constraint equations, is appropriately linearized. Barlat's strain-rate potential is employed, whose in-plane anisotropic properties are taken into account with anisotropic coefficients and potential parameters. The linear triangular membrane elements are used for depicting the formed sheet. In the numerical simulations of deep drawing processes of a flat-top cylindrical cup for 2090-T3 aluminum alloy sheet show good agreement with experiments, although some discrepancies were observed in the directional trend of cup height and thickness strains.

• Transactions of Materials Processing
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• v.20 no.8
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• pp.562-567
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• 2011

This paper deals with effects of certain important factors in a tube drawing operation, such as the use of a mandrel, die radius and tangential angle at die outlet, on the deformation behavior of a small-diameter seamless tube. Both experimental and finite element simulation studies are carried out to assess the effects of the above parameters. Experiments and finite element predictions are compared. The use of a mandrel simplifies the design of tube drawing, but also induces some difficulties from increased process complexity. The effects of die outlet tangential angle and radius are discussed in detail.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1994.03a
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• pp.118-128
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• 1994

The planar anisotropic FEM analysis for predicting the earing profiles and draw-in amounts in the deep-drawing processes is introduced. An implicit, incremental, updated Lagrangian formulation with a rigid-viscoplastic constitutive equation is employed. Contact and friction are considered through the mesh-based unit vectors and the normal contact pressure. the consistent full set of governing relations, comprising equilibrium and geometric constraint equations, is appropriately linearized. Barlat's strain-rate potential is employed, whose in-plane anisotropic properties are taken into account with anisotropic coefficients and potential parameter. The linear triangular membrane elements are used for depicting the formed sheet. with the numerical simulations of deep drawing processes of flat-top cylindrical cup for the 2090-T3 aluminum effects on the earing behavior are examined. Earing predictions made for the 2090-T3 aluminum alloy sheet show good agreement with experiments, although some discrepancies were observed in the directional trend of cup height and thickness strains.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2009.05a
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• pp.236-239
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• 2009

Cowl cross bar, a component of automotive cockpit module, has been manufactured by using welding processes of several tube parts with different diameters. However, in order to reduce costs and increase the quality, it is required to develop a new production method to manufacture the cowl cross bar as one-piece In this study, therefore, eliminating the welding process, tube drawing process which is one of metal forming processes was designed by using combined drawing technique. In addition, the selectable range of area reduction ratio was defined as a design guideline and the designed process sequence was verified by finite element analysis.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.05a
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• pp.151-155
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• 2001

The purpose of this study is to investigate the weldline movement of the laser welded sheets during the warm deep drawing process. For this investigation, Five steps of temperature ranges, from room temperature to $200^{\circ}C$, and two kinds of thickness combination, 0.8 mm${\times}$1.2 mm and 0.8 mm${\times}$1.6 mm SCP1 material sheets, were adopted. Also, the numerical analysis using the PAM-STAMP has been carried out with the same models as the specimens. As a result the higher temperature was adopted, the less weld-line movement was observed.

• Journal of The Korean Association For Science Education
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• v.32 no.9
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• pp.1417-1426
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• 2012

The purpose of this study was to analyze elementary school students' understanding of the human body by drawing the human organism. Data was gathered by open questionnaires of drawing for human body. The open questionnaire was taken with 530 elementary school students from 3rd to 6th grade. The results were as following: First, elementary school students show the highest understanding of the skeletal system, the digestive systems, the respiratory systems, the circulating system and the muscular system respectively. Second, elementary school students' understanding of the human body improved as the grade goes up. Third, it seems that elementary school students have had their own knowledge about the human body through environmental surroundings before learning about the human body.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.05a
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• pp.393-396
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• 2005

This paper is concerned with the drawing process of $Al-1\%Si$ bonding wire. In this study, the finite-element model established in previous work was used to analyze the effect of various forming parameters, which included the reduction in area, the semi-die angle, the aspect ratio, the inter-particle spacing and orientation angle of the fine Si particle in drawing processes. The finite-element results gave the consolidation condition. From the results of analysis, the effects of each forming parameter were determined. It is possible to obtain the Important basic data which can be guaranteed in the fracture prevention of $Al-1\%Si$ wire by using FE-Simulation.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2008.05a
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• pp.450-453
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• 2008

During the drawing of reentrant section like a spline, the unfilled in the corner of dies or the bended product emerges from the large reduction of area, the complex shaped sections and other nonuniform properties in material and lubrication conditions. In this study, the drawing of the spline section with the non-rotary symmetry from a circular aluminum billet has been analyzed by using commercial code DEFORM-3D. A new die construction method preventing the spline from the drawback of bending and the unfilled defect has been suggested and verified through the analysis using centroid shift method and the hybrid construction between converged and diverged profile.

• Journal of the Korean Society of Mechanical Technology
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• v.20 no.6
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• pp.796-802
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• 2018

In order to remove rust and impurities from surface of raw SUS circular bar, peeling machine is used to make lustrous and clean surface of SUS circular bar. Drawing process system is used to manufacture SUS hexagonal bar. SUS hexagonal bar have been widely used to make hexagonal bolt/nut, adapter and fittings and so on. The purpose of this study is to investigate the stabilities for guide bar of clamp in drawing process system. As the results, the guide bar showed structural stability in cases of below load of 50 Ton and over hook radius of 3.0mm. Further as the thickness of guide bar hooking with jaw was increased, minimum safety factor was decreased.

• Transactions of Materials Processing
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• v.19 no.8
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• pp.508-516
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• 2010

Thickening process in sheet metal forming is being increased to improve the strength as well as to reduce manufacturing process such as welding. This process can make it possible to obtain part locally thicker than that of initial sheet thickness. In this study, design method for manufacturing the component which has double sinks with local thickened wall is proposed. Deep drawing and upsetting processes are applied in order to form double sinks and thicken its walls. Used material is SPHC440 with the thickness of 2.0mm and initial blank size is determined on the basis of the final product. Distance between the center of double sinks and first drawing ratio to avoid fracture are the most significant factors during deep drawing. FE-analysis is implemented in order to determine the appropriate values. Progressive die is designed based on the proposed method and FE-analysis. As a result of experiment, locally thickened component can be manufactured, which has double sinks with the thickness about 3mm at the corner and wall.