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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 5, Issue 4 - Dec 1996
Volume 5, Issue 3 - Sep 1996
Volume 5, Issue 2 - Jun 1996
Volume 5, Issue 1 - Mar 1996
Selecting the target year
Press Hardening공정의 자동차 부품 적용 동향
Transactions of Materials Processing, volume 5, issue 4, 1996, Pages 263~268
Application of Genetic Algorithm to Die Shape Otimization in Extrusion
Transactions of Materials Processing, volume 5, issue 4, 1996, Pages 269~280
A new approach to die shape optimal design in extrusion is presented. The approach consists of a FEM analysis model to predict the value of the objective function a design model to relate the die profile with the design variables and a genetic algorithm based optimaization procedure. The approach was described in detail with emphasis on our modified micro genetic algorithm. Comparison with theoretical solutions was made to examine the validity of the predicted optimal die shapes. The approach was then applied to revealing the optimal die shapes with regard to various objective functions including those for which the design sensitivities can not be deter-mined analytically.
Experimental Study on the Deep Drawing Process for L-shape Cross Section
Transactions of Materials Processing, volume 5, issue 4, 1996, Pages 281~287
Two kinds of blank shapes optimum and square are adopted to investigate formability. Optimum blank shape is determined to construct an L-shape cup with uniform height and without flange part. For this purpose rigid-plastic FEM analysis is applied with backward tracing technique. Maximum cup depth and strain distribution are measured experimentally for the products of the two kinds of blank shapes which are optimum and square. it is confirmed that deeper cup without severe thickness reduction can be obtained from the optimum shape.
Experimental Study on the Multi-stage Deep Drawing Process
Transactions of Materials Processing, volume 5, issue 4, 1996, Pages 288~296
A method of determining an optimum blank shape for non-circular deep drawing process is extended to the multi-stage deep drawing process. As an example concentric two-stage square deep drawing process is considered and the ideal blank shape with uniform cup height and without flange part after the process is constructed by the backward tracing of rigid plastic FEM. The conventional square blank shapes are also adopted for the comparison of two cases. As a result it is confirmed that the drawn products with better thickness strain distribution and deeper cup depth could be obtained by the suggested ideal blank shapes.
Finite Element Analysis for Steady State Forming Process of Polycrystalline Metal Including Texture Development
Transactions of Materials Processing, volume 5, issue 4, 1996, Pages 297~304
A process model is formulated considering the effect of crystallographic texture developed in forming process. The deformation induced plastic anisotropy can be predicted by capturing the evolution of texture during large deformation in the polycrystalline aggregate. The anisotropic stiffness matrix for the aggregate is derived and implemented in Eulerian finite element code using a Consistent Penalty method. As an application the evolution of texture in rolling drawing and extrusion processes are simulated. The numerical results show good agreements with report-ed experimental textures.
Prediction of Recrystallization Behaviors in Hot Forging by the Finite Element Method
Transactions of Materials Processing, volume 5, issue 4, 1996, Pages 305~319
In this paper a finite element based system is presented for the prediction of the distributions of the recrystallized grain sizes in the workpiece in hot forging. The system adopts a fully coupled finite element thermo-mechanical model for predicting plastic deformation and heat transfer occurring in the workpiece and employs existing metallurgical models relating the recrystalliza-tion behavior with the thermo-mechanical variables such as temperatures strain and strain rate. The system is applied to upsetting of cylindrical preform. The predicted grain sizes are compared with the measurements. It is further applied to forging of a complex-shaped product.
Rotation of Orthotropy Axes with Work Hardening of Anisotropic Sheet Metals
Transactions of Materials Processing, volume 5, issue 4, 1996, Pages 320~326
Based upon experimental observations the authors have shown in the previous studies that the orientations of orthotropy axes of anisotropic sheet metals are subjected to change during tensile loading at angles to the rolling direction. To predict the rotations of orthotropy axes under general plane stress conditions, a simple phenomenological model is proposed which accounts for the effect of work hardening. Predictions from the model are compared against the experiments for 0%, 3%, and 6% of 1st tensile prestrains in the rolling direction and 2nd tensile prestrains at 30
to the 1st prestrains axis. The model showed good agreements with the experimental observations. A new interpretation of the experimental data is suggested regarding the rotations of orthotropy axes.
The Effect of Dynamic Strain Aging on the High Temperature Plastic Deformation Behaviour of Al-Mg Alloy
Transactions of Materials Processing, volume 5, issue 4, 1996, Pages 327~336
The effect of dynamic strain aging on high temperature deformation behaviour of the A-Mg alloy was investigated by strain rate change tests and stress relaxation tests between 20
. Yield point, short stress transient and periodic discontinuities on the stress-strain curve were considered as an evidence of the effect of dynamic strain aging. With this criterion two distinct strain rate-temperature regimes could be manifested. Dynamic strain aging was considered to be effective in the high temperature-low strain rate regime, whereas dynamic recovery was a dominant deformation mechanism in the low temperature-high strain rate regime. It was found that dynamic strain aging in the high temperature deformation was governed by the mechcanism of diffusion-controlled, viscous dislocation movement.
Ductile Fracture in the Central Region of Circular Plate in Rotary Forging
Park, Seogou ; Oh, Hung-Kuk ;
Transactions of Materials Processing, volume 5, issue 4, 1996, Pages 337~342
The present investigation is concerned with application of theory on fracture to the prediction of workability of materials in rotary forging with special reference to center crack. The validity of the theory on ductile fracture was examined by the experimental data. Then the workability of materials in rotary forging was determined.
Further Development of Vision-Based Strain Measurement Methods to Verify Finite Element Analyses
Kim, Hyung jong ; Lee, Daeyong ;
Transactions of Materials Processing, volume 5, issue 4, 1996, Pages 343~352
One of the preferred methods that can be used to verify the results of finite element analysis is to measure surface strains of the deformed part for purpose of direct comparison with simulation results. Instead of using the usual manual method the vision-based measurement method is capable of determining surface geometry and strain from the deformed grid pattern automatically with the help of a computer. To obtain strain distribution over an area, the coordinates of such a surface grid are determined from the multiple video images by applying the photogrammetry principle. Methods to improve the overall accuracy of the vision-based strain measurement system are explored and the possible accuracies that can be attained by such a measurement method are discussed. A major emphasis is placed on the initial grid application method its accuracy and ease of subsequent image processing. Finite element analyses of limiting dome height(LDH) test are carried out and the results of them are compared with exsperimen-tal data.