• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.296-299
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• 2002

The precision blanking of thin sheet metal is important process on production of precision electronic machine parts such as IC leadframe. In the blanking process, the factors that friction coefficient, tool clearance, material properties are the most important factors in the precision blanking process, because these factors affect the sheared face of product, side forces to punch during blanking process and surface condition after blanking process. So, many investigations have been performed. But, the former studies did not take up the characteristic of material. In this paper, in order to investigate the characteristic of blank, such as K(strength coefficient) and n(strain hardening coefficient), on the sheared face of blank and the side force to punch, FE-simulation has been analyzed by means of DEFORM-2D. To obtain input Parameters on FE-simulation, tensile and friction test has been done.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 추계학술대회 논문집
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• pp.255-258
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• 2005

In this study, the effect of heat treatment conditions and deformation temperature on the formability were investigated in warm hydroforming of Al 6061 tube. Full annealing and T6-treatment for heattreatment of Al6061 tube were used in this study. To evaluate the hydroformability, uniaxial tensile test and bulge test were performed between room temperature and $300^{\circ}C$. And measured flow stress was used to simulate the hydroforming of Al 6061. A commercial FEM code, DEFORM2D, was used to calculate the damage and strain variation. The calculated values were efficient to predict the forming limit in hydroforming for real complex shaped part.

• 한국정밀공학회지
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• 제22권10호
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• pp.49-55
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• 2005

The objective of this study was presented with a prediction on the alignment of cementite in pearlite lamella structure of high carbon steel by means of finite-element method(FEM) simulation. Pearlite strcuture was characterized by its nano-sized microstructure feature of alternation ferrite and cementite. FEM simulations were performed based on a suitable FE model describing the boundary conditions and the material behavior. With the alignment of lamella structure in high carbon pearlite steel wire, material plastic behavior was taken into account on plastic deformation and alignment of cementite. The effects of many important parameters(reduction in area, semi-die angle, initial angle of cementite ) on wire drawing process were predicted by DEFORM-2D. As the results, the possibility of wire fracture could be considerably reduced and the productivity of final product could be more increased than before.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2009년도 춘계학술대회 논문집
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• pp.129-134
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• 2009

The dimension of forged part is different from that of die. Therefore, a more precise die dimension is necessarys to produce the precise part, considering the dimensional changes from forging die to final part. In this paper, both experimental and FEM analysis are performed to investigate the effect of several features including die dimension at each forging step and heat-treatment on final part accuracy in the closed-die upsetting. The dimension of forged part is checked at each stage as machined die, cold forged, and post-heat-treatment steps. The elastic characteristics and thermal influences on forging stage are analyzed numerically by the DEFORM-$2D^{TM}$. The effect of residual stress after heat-treatment on forged part could be considered successfully by using DEFOAM-$HT^{TM}$.

• 소성∙가공
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• 제20권4호
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• pp.291-295
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• 2011

The injector housing has two functions, namely, positioning the injector and protecting it from coolant. The conventional manufacturing process of the injector housing by machining has some drawbacks such as considerable loss of material and environmental pollution caused by excessive use of cutting oil. In this paper, precision cold forging is proposed as a new manufacturing process in order to improve these issues. A numerical study was conducted to compute the metal flow, strain, load and other process variables using DEFORM-2D, a finite element analysis(FEA) code for metal forming. Two process methods were investigated and optimal conditions were computed with the FEA code. A prototype was manufactured from the optimal process method and the metal flow and hardness were obtained from the prototype.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 추계학술대회 논문집
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• pp.53-57
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• 2002

Brake tube is considered one of the most important parts in automobile. The shape of brake tube-end has a great influence on the function of brake, and the quality and productivity of brake tube have relation to die design. The forming process of brake tube-end is peformed by hydraulic press forming machine. In this paper, the forming processes of tube-end for automobile is analyzed and designed to make the optimal form of brake tube-end. Also, finite element analysis has been carried out using DEFORM-3D$\^$TM/ to predict the optimal shape of brake tube-end and the results obtained showed the optimal length between punch and chuck is 1.0 ∼ 1.2mm. The shape of tube-end is in good agreement with the finite element simulations and the experimental results.

• 한국공작기계학회논문집
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• 제10권6호
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• pp.63-70
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• 2001

This study is concerned with Finite Element Analysis on welded part of control link fur automobile. For analysis, control link was modeled into two parts, ring and rod. Heating condition, temperature distributions and fatigue fracture strength were analyzed using "HEAT III" and "NDURE" module of NISA II. Metal flow in the process of welding was simulat- ed by $DEFORM^{TM}2D$.The analyzed results were compared with experimental inspection. Quality of welded part was able to be improved by controlling metal flow in the process of welding by increase the friction constant of ring part. Heat transfer analysis and flow simulations were in good agreement wish welding experiments.

• 한국정밀공학회지
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• 제17권1호
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• pp.209-215
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• 2000

Precision forging technology that can control flow velocity of workpiece have been developed to minimize the amounts of machining. To get the uniform rib length, flow velocity distribution is needed to be estimated and controlled. Computer-aided design is known for very effective to estimate the deformation behavior and design the die for controlling the flow velocity. In this study, die design to control the deformation velocity are investigated using the DEFORM-2D about rib-web shape parts. Also we can get uniform rib length by enforcing the back pressure at end section of rib. The applied load of back pressure farming is lower than that of conventional forging. These results are analysed and confirmed by the experiment.

• 한국멀티미디어학회논문지
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• 제22권4호
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• pp.491-501
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• 2019

Variational methods, which cast deformation as an energy-minimization problem, are known to provide a good trade-off between practicality and speed. However, the time required to deform a fully detailed shape means that these methods are largely unsuitable for real-time applications. We simplify a 2D shape into a curve skeleton, which can be deformed much more rapidly than the original shape. The curve skeleton also provides a simplified control for the user, utilizing a small number of control handles. Our system deforms the curve skeleton using an energy-minimization method and then applies the resulting deformation to the original shape using linear blend skinning. This approach effectively reduces the size of the variational optimization problem while producing deformations of a similar quality to those obtained from full-scale nonlinear variational methods.

• 대한금속재료학회지
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• 제47권9호
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• pp.567-572
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• 2009

The densification behaviors of mixtures of copper and steel powders during cold die compaction were investigated. We proposed the pressure-dependent yield function based on the rule of the mixtures of each yield function of a critical relative density type. The constitutive equations were implemented into a finite element program (DEFORM2D) to analyze the densification and deformation behavior of powder mixtures, and the simulated results are in good agreement with the experimental results in reference studies.