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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Transactions of Materials Processing
Journal Basic Information
Journal DOI :
The Korean Society for Technology of Plasticity
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Volume & Issues
Volume 6, Issue 6 - Dec 1997
Volume 6, Issue 5 - Oct 1997
Volume 6, Issue 4 - Aug 1997
Volume 6, Issue 3 - Jun 1997
Volume 6, Issue 2 - Apr 1997
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On the Springback Analysis of Sheet Metal Forming
Transactions of Materials Processing, volume 6, issue 5, 1997, Pages 386~394
The analysis of the springback is done based on the stress of sheet after forming. Therfore, it is important to get the accurate stress from forming analysis. In this study, some parameters that influence on the accuracy of the springback estimation are investigated. Discretization of sheet and tools, choice of penalty constant and damping in contact treatment, and tool speed scaling are chosen as parameters. As a numerical example, the 2D draw bending benchmark problem of the NUMISHEET'93 is used. Also, the springback results of the s-rail benchmark problem of the NUMISHEET'96 are presented.
Reduced Finite Element Simulation of Cold Forging Processes Based on the Forming Experiment
Lee, Chung-Ho ;
Transactions of Materials Processing, volume 6, issue 5, 1997, Pages 395~399
There exists a certain functional relation between Vickers hardness and flow stress in the strain-hardened material. Using this relation, the Vickers hardness values in the strain-hardened material can be converted into the flow stress values in good approximation. Therefore, the information about the flow stress distribution in the material can be easily acquired through a forming experiment. That makes it possible to simulate the process state for a critical moment of cold forging under the given boundary conditions very quickly without calculating the foregoing history of the actual deformation from the beginning.
Blank Design System for Sheet Forming
Transactions of Materials Processing, volume 6, issue 5, 1997, Pages 400~407
Geometric mapping technique has been used to find the shape of initial blank for sheet forming. The method was chosen because of its simplicity and numerical efficiency. Error in blank shape were measured along deformation path by FE analysis of forming. Blank shape was modified by volume additionaddition/Subtractiontraction method with taking with taking into account of deformation path. Modified blank shape shows an acceptable result, showing the current method can be an useful tool for predicting blank shape in the practical application. More test will be done to verify the validity of the method.
Process Design in Coining by Three-Dimensional Backward Tracing Scheme of Rigid-Plastic Finite Element Method
Transactions of Materials Processing, volume 6, issue 5, 1997, Pages 408~415
The backward tracing scheme of the finite element analysis, which is counted to be unique and useful for process design in metal forming, has been developed and applied successfully in industry to several metal forming processes. Here the backward tracing scheme is implemented for process design of three-dimensional plastic deformation in metal forming, and it is applied to a precision coining process. The contact problem between the die and workpiece has been treated carefully during backward tracing simulation in three-dimensional deformation. The results confirm that the application of the developed program implemented with backward tracing scheme of the rigid plastic finite element leads to a reasonable initial piercing hole configuration. It is concluded that three-dimensional extension of the scheme appears to be successful for industrial applications.
A General Tool Surface Contact Search and its Application to 3-D Deep drawing Process
Transactions of Materials Processing, volume 6, issue 5, 1997, Pages 416~424
In the present study, a contact search and check algorithm for general tool surface described by triangular FE patch is proposed. To improve numerical stability, SEAM element using the linear Coons interpolation has been used. To check the proposed algorithm, both clover cup and L-shape cup deep drawing processes are calculated. The computed results shows that the proposed contact algorithm can be successfully applied for sheet metal forming processes with general shaped tools.
Characterization of superplastic material SPF8090 AI-Li with the variation of the strain rate and the temperature
Transactions of Materials Processing, volume 6, issue 5, 1997, Pages 425~434
A superplastic material, aluminum-lithium alloy 8090, was examined with uniaxial tensile tests to investigate its thermomechanical behavior. The tests were carried out at the strain rate ranging from
and at the temperature from 48
. The experiments produced force-dis-placement curves which were converted to stress-strain curves. From the curves, the optimum conditions of superplastic forming were obtained by deteriming the strain rate sensitivety, the optimum strain rate, and the strength coefficient for various forming temperatures.
A Study on the Mechanical Properties of Connecting Rod Manufactured by Direct Quenching
Transactions of Materials Processing, volume 6, issue 5, 1997, Pages 435~445
In order to study the manufacturing possibility of connecting rod by direct quenching method, the difference between connecting rod by direct quenching and that by general heat treatment were investigated by observing microstructure, by measuring mechanical properties, by conducting fatigue testing, and by measuring the amount of tool wear in actual cutting. Connecting rod manufactured by direct quenching had better fatigue life than that by general heat treatment, which was due to homogeneous microstructure, and higher strength. The amount of cutting tool wear of connecting rod by direct quenching was higher than that by general heat treatment, which was due to low machinability and high toughness of tempered martensite microstructure. Therefore it will be added the study of heat treatment and cutting condition for manufacturing by direct quenching.
Analysis and Design of a Forming Porcess for Combined Extrusion with Aluminum AIIoy 7075
Transactions of Materials Processing, volume 6, issue 5, 1997, Pages 446~455
A Combined extrusion operation consists of forward and backward extrusion forming and it is possible to make the process be simple by employing it. But the metal flow pattern induced by the operation is hard to analyze accurately because the flows are non-steady, which have at least two directions dependent upon each other. So engineers in the industrial factories had conducted the two extrusion operations separately