• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1998.03a
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• pp.94-99
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• 1998

In bulk metal forming processes prediction of tool life is very important for saving production cost and achieving good material properties. Generally the service life of tools in metal forming process is limited to a large extent by wear, fracture and plastic deformation of tools. In case of hot and warm forging processes, tool life depends on wear over 70%. In this study finite element analyses are applied to warm forging and hot forging by adopting suggested wear model. By comparision of simulation and real profile of die, suggested model is verified

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 1997.03a
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• pp.37-41
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• 1997

Tailored Blanks are defined as two or more separate pieces of sheet material having the same or dissimilar thickness and/or physical properties, joined together before forming. Its application is being increased especially in the automotive industrial area for the cost reduction, weight saving, and improvement of strength. In this paper, the deforming behaviour of the laser welded blanks with regard to different thicknesses and combinations are described through some experimental investigations on the formability of a door inner. To investigate how the combination of thickness and material property influences the movement of welding line, a series of laser welded T/B blanks are tested.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.19 no.6
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• pp.746-752
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• 2010

Rib structure has been used to bed and column of machine tool to heighten weight stiffness ratio, cost performance and weight saving. In this paper the bed rib structure was estimated with thermal characteristics. Using superposition principle, machine tool designer can describe every complicated heat generation in the machine tool thermal source. As thermal characteristics, thermal deformation of guide rail and column and Maximum-minimum temperature variation were selected. The size, configuration and direction against the thermal loading surface operated to the thermal characteristics. The DB chart was made following rib structure estimating thermal characteristics. With superposition principle and DB chart, machine tool designer can prognosticate the thermal characteristics without FEM analysis to every bed rib structure.

• Journal of the Korean Applied Science and Technology
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• v.26 no.3
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• pp.233-239
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• 2009

A reaction device raising a generation yield by efficiently removing water generated in an esterified reaction between diethylene glycol monoethyl ether and succinic acid with mixture of an azeotropic point was newly developed as a new product in development of more stabilized emulsifier with a semi-solid phase(cream) in an emulsified phase of interfacial activity. The bis-(diethylene glycol monoethyl ether succinate(hereinafter, called as BDGS) with a high yield of more than 95% was obtained. As this has a property containing amphoteric emulsified functions such as W/O type or O/W type, etc., and has a merit that can be used regardless of any emulsified phase, there is no need using other emulsified surfactant. therefore, as this has excellent skin wetability in the cosmetics industry, a product having a wider range in quality compatibility or cost saving, etc. as a humectant has been developed.

• Journal of Information Display
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• v.10 no.2
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• pp.87-91
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• 2009

Highly efficient red phosphorescent OLEDs (PHOLEDs) with a simple, organic, triple-layer structure was developed using the narrow-bandgap fluorescent host material bis(10-hydroxybenzo[h] quinolinato)beryllium complex (Bebq2) and the deep-red dopant tris(1-phenylisoquinoline)iridium (Ir(piq)3). The maximum current and power efficiency values of 12.71 cd/A and 16.02 lm/W, respectively, with an extremely low doping technology of 1%, are demonstrated herein. The results reveal a practical, cost-saving host dopant system for the fabrication of highly efficient PHOLEDs involving the simple structure presented herein, with a reduction of expensive Ir dopants.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.414-417
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• 2005

Many process parameters have an effect on the auto-body panel forming process. A well-designed blank shape causes the material to flow smoothly, reduces the punch and yields a product with uniform thickness distribution. Therefore, the determination of an initial blank shape plays the important role of saving time and cost in the auto-body panel forming process. For these reasons, some approaches to estimate the initial blank shape have been implemented in this paper, the one-step approach by using a finite element inverse method will be introduced to predict the initial blank shape the developed program is applied to auto-body panel forming.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.67-70
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• 2005

The static implicit finite element method is applied effectively to analyze total roof panel stamping processes, which include the forming stage. complicated and abnormal Large size roof panel was analyzed by using commercial program called AutoForm. Analysis results examining possibility and validity of the AutoForm software and the factor study are presented. Further, the simulated results for the total roof panel stamping processes are shown and discussed. Its application is being increased especially in the automotive industrial area for the cost reduction, weight saving, and improvement of strength.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.210-213
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• 2005

Recently a number of parts have a tendency to be a module for saving weight, cost, process and high quality in automotive industry. The forming process to combine automotive rack tube which was consisted on many parts is various. This paper presents tube forming process using elasto-forming process. We investigated the properties of rubber and tube by Finite Element Analysis. And it was compared with the experimental results for the formability of tube. we was to suggest a forming process using moving die for elasto-forming process, and through this improvement we could get the good formability.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.75-78
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• 2005

The static implicit finite element method is applied effectively to analyze back inner panel stamping processes, which include the forming stage Analysis results examining possibility and validity of the formulation and the factor of study are presented. Further, the simulated results for f/apron panel stamping processes are shown and discussed. Its application is being increased especially in the automotive industrial area for the cost reduction, weight saving, and improvement of strength.

• Transactions of Materials Processing
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• v.19 no.4
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• pp.210-216
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• 2010

The importance and interests for saving of energy and cost in industry has grown up. Therefore, process optimization to reduce the process and energy become one of the most important things. The non-heat treated steel, post-heat-treated is no necessary, has attractive points as structural materials. However, establishment of mechanical properties is necessary to apply non-heat-treated steel to structural parts. In this study, for non-heat-treated steel and pre-heat-treated steel, we have investigated microstructure, hardness, the tensile strength, compressive strength. And the FE analysis technology to predict the hardness value of forged part is developed on micro-alloyed steel forged part.