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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Transactions of Materials Processing
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Journal DOI :
The Korean Society for Technology of Plasticity
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Volume & Issues
Volume 11, Issue 8 - Dec 2002
Volume 11, Issue 7 - Nov 2002
Volume 11, Issue 6 - Oct 2002
Volume 11, Issue 5 - Sep 2002
Volume 11, Issue 4 - Aug 2002
Volume 11, Issue 3 - Apr 2002
Volume 11, Issue 2 - Apr 2002
Volume 11, Issue 1 - Feb 2002
Selecting the target year
Hydroming Process Automotive Applications
Transactions of Materials Processing, volume 11, issue 4, 2002, Pages 285~294
DOI : 10.5228/KSPP.2002.11.4.285
Trends and Automotive Applications of Hydroforming
Transactions of Materials Processing, volume 11, issue 4, 2002, Pages 295~301
DOI : 10.5228/KSPP.2002.11.4.295
Recently, design concepts of vehicle will have to consider the safty and economy of fuel consumtion. The hydroforming technology has applied to increase strength, and to decrease weight, cost and part count. The hydroforming has been recognized as general technique in automotive industry. This paper deals with the trends of automotive application of hydroforming, new hydroforming technologies, facilities.
Numerical Study on Analysis and Design of Tube Hydroforming Process by the FEM
Transactions of Materials Processing, volume 11, issue 4, 2002, Pages 302~311
DOI : 10.5228/KSPP.2002.11.4.302
A generalized numerical approach based on the finite element method to analysis and design of hydroforming process is proposed in this paper. The special attention is focused on comparison of an implicit and an explicit finite element method widely used for hydroforming simulation. Furthermore, in order to meet the increasing real needs for prediction of forming limit, a ductile fracture criterion combined with finite element method is introduced and then applied to hydroforming process of an automobile lower m Consequently, the numerical analysis and design for hydroforming process presented here will facilitate the development and application of the tube hydrofoniung process to a new level.
The Effect of Plunger Tip Shape on the Formability in Semi-Solid Die Casting Process
Transactions of Materials Processing, volume 11, issue 4, 2002, Pages 312~322
DOI : 10.5228/KSPP.2002.11.4.312
In this study, an innovative semi-solid die casting technology to replace heavier cast iron compressor parts with lightweight aluminum castings was proposed, and the application possibility for home-appliance component was investigated. The most important factors regarding the semi-solid die casting process are the reheating process of the raw materials to the semi-solid state, specifications of the forming machine, the optimal injection conditions and die design. Materials used in this study were A3S7 and hSn alloys fabricated by the electromagnetic stirring process. The optimal injection conditions for semi-solid die casting process were Presented with the reheating conditions of the semi-solid materials. To investigate the effect of plunger tip shape on the formability and mechanical properties in semi-solid die casting process for complicated shape part, two kinds of plunger tip shape with long and short plunger tip taper are proposed.
Study on Rapid Manufacturing of 3D Functional Parts Combining VLM-ST Process and Its RT Technology
Transactions of Materials Processing, volume 11, issue 4, 2002, Pages 323~331
DOI : 10.5228/KSPP.2002.11.4.323
The combination of rapid prototyping(RP) and rapid tooling(RT) has a potential for rapid manufacturing of three-dimensional parts. In the present study, a new RP system transfer type Variable Lamination Manufacturing using Expandable Polystyrene Foam (VLM-ST), is proposed to fabricate net shapes of three-dimensional prototypes. Various three-dimensional parts, such as a knob shape and a human head shape, are manufactured by the VLM-ST apparatus. In addition, a new rapid tooling technology, which utilizes a room temperature vulcanizing (RTV) molding technique and a triple reverse process technique, is proposed to manufacture net shapes of three-dimensional plastic parts using the prototypes of VLM-ST. A plastic part of the knob shape is produced by the proposed RT technology. The combination of the proposed RP and RT enables the manufacture of a plastic knob within two days.
A Study on the Injection Molding for the tight Guide Plate of a Small Sized LCD (1) : finite Element Analysis and Mold Design
Transactions of Materials Processing, volume 11, issue 4, 2002, Pages 332~340
DOI : 10.5228/KSPP.2002.11.4.332
The light guide plate of the TFT-LCD reflects the light originated from the light source, and guides the light to the front side of LCD so that we can see images vividly. This paper is concerned with tile injection molding of the light guide plate for the reflective typed LCD related to IMT-2000. The finite element analysis has been carried out based on the pine stress theory to predict both the thermal stresses of the products in the post-filling stage and the in-plane deformation behavior of the products after ejection process. Based on the simulation results, the mold for the light guide plate of a 2inch sized LCD has been designed.
A Study on the Injection Molding for the Light Guide Plate of a Small Sized LCD (2) : Influences of Processing Conditions on the Brightness
Transactions of Materials Processing, volume 11, issue 4, 2002, Pages 341~348
DOI : 10.5228/KSPP.2002.11.4.341
For the light guide plate of the TFT-LCD, there have been increasing demands for higher brightness, thin and light-weight design, and lower power consumption. To meet these demands, a micro-prism-type frontlight that integrates a prismatic sheet and a light-guiding plate has been developed. In this paper, the influences of processing conditions on the brightness were studied lot the injection molding of the light guide plate. Based on the experiment with an actual mold, the design of experiments and the neural network theory were used lot choosing the optimal processing parameters to increase the brightness and the uniformity. The verification experiment also showed that the brightness and the uniformity were increased dramatically with the chosen processing conditions.
Friction Model for Sheet Metal Forming Analysis (Part1 : Experiment)
Transactions of Materials Processing, volume 11, issue 4, 2002, Pages 349~354
DOI : 10.5228/KSPP.2002.11.4.349
In order to find the effect of lubricant viscosity, sheet surface roughness, tool geometry, and forming speed on the frictional characteristics in sheet metal forming, a sheet metal friction tester was designed and manufactured and friction test of various sheet were performed. Friction test results showed that as the lubricant viscosity becomes lower, the friction coefficient is higher. When surface roughness is extremely low or high, the friction coefficient is relatively high. The result also show that as the punch radius and punch speed becomes bigger, the friction coefficient is smaller. Using experimental results, the mathematical expression between friction coefficient and lubricant viscosity, surface roughness, punch comer radius, or punch speed is also described.
Elastic Analysis of Cold Extrusion Die Set with Stress Ring
Transactions of Materials Processing, volume 11, issue 4, 2002, Pages 355~362
DOI : 10.5228/KSPP.2002.11.4.355
In this study, an axi-symmetric finite element program for elastic analysis of the die set shrink fitted in cold extrusion was developed. The geometrical constraint according to shrink fit was enforced by employing the Lagrange multiplier method. The numerical results for strain and stress distributions in the die set including single and multi stress rings assembled by shrink fit were compared well with the Lame's equation for thick-walled solution available in the literature. To extend the applicability of the analysis program developed, various cases without or with stress ring and with pre-stress applied on stress ring were numerically investigated as well. This numerical approach enables the optimization study to determine optimal dimensions of die set to improve tool life for practical use in industry.
Optimal Design of Dimension of Extrusion Die with Single Stress Ring
Transactions of Materials Processing, volume 11, issue 4, 2002, Pages 363~370
DOI : 10.5228/KSPP.2002.11.4.363
In this study, an optimal design technique was investigated for determining appropriate dimensions of components of the die set used in the extrusion process. For this, an axi-symmetric elastic finite element program for the analysis of deformation of the shrink fitted die set was developed with the Lagrange multiplier method to implement the constraint condition of shrink fit of stress ring. By coupling the rigid-viscoplastic analysis of extrusion process by CAMPform and elastic analysis of the die set, the optimization study was made by employing optimization program DOT. Considering the various assembly conditions, optimal design was determined for a single stress ring case. It is construed that the proposed design method can be beneficial for improving the tool life of cold extrusion die set at practice.