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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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Sectional Forming Analysis of Stamping Processes for Luminum Alloy Sheet metals
Transactions of Materials Processing, volume 6, issue 4, 1997, Pages 279~290
The sectional forming analysis of stamping pocesses for aluminum alloy sheet metals was investigated. For the modeling of the anomalous behavior of aluminum alloy sheet. the Barlat's strain rate potential and Hill's 1990 non-quadratic yield theory with an isotropic hardening rule were employed. The rigid-viscoplastic FEM formulation which solves equilibrium equation for plane-strain stage with mesh-normal geometric constraints was derived. A new method to determine the Barlat's anisotropic coefficients was also suggested. To verify the validity of the formulation, the stretch and draw forming processes of a square cup were simulated.
Process Sequence Design of the Inner Skin of Landing Gear Using Stretch Forming Process
Transactions of Materials Processing, volume 6, issue 4, 1997, Pages 291~299
This paper is concerned with the design of process sequence to form the inner skin of landing gear. The inner skin of landing gear is a part of airplane which is known to be difficult to form its shape. Our study investigates the production method of inner skin and examines the design criteria by three dimensional elastic-plastic finite element method. Based on the results of simulation, design strategy for improving the process sequence is developed using stretch forming process. The final product of inner skin is produced in multi-stage operations with annealing treatment to meet the required capacity of press. The numerical results show that the newly designed process can produce the required part successfully within the design criteria.
Design of Porcess Parameters in Axisymmetric Multi-step Deep Drawing by a Finite Element Inverse Method
Transactions of Materials Processing, volume 6, issue 4, 1997, Pages 300~310
A finite element inverse method is introduced for direct prediction of blank shapes, strain distributions, and reliable intermediate shapes from desired final shapes in axisymmetric multi-step deep drawing processes. This mothod enables the determination of process disign. The approach deals with the Hencky's deformation theory. Hill's second order yield criterion, simplified boundary conditions, and minimization of plastic work with constraints. The algorithm developed is applied to motor case forming, and cylindrical cup drawing with the large limit drawing ratio so that it confirms its validity by demonstrating resonably accurate numerical results of each problem. Numerical examples reveal the reason of difficulties in motor case forming with corresponding limit diagrams.
Simulation of Compression Molding with Extensional & Shear Viscosity for Fiber-Reinforced Polymeric Composites
Transactions of Materials Processing, volume 6, issue 4, 1997, Pages 311~318
In recent years, compression molding of fiber-reinforced thermoplastics has been increased in commercial aspects. During a compression molding process of composites, the flow analysis must be developed in order to accurately predict the finished part properties as a function of the molding process parameters. In this paper, a new model is presented which can be used to predict the flow under consideration of the slip of mold-composites and extensional & shear viscosity ratio M and slip parameter
on the mold filling parameters are discussed.
Finite Element Analysis of r Deformation Behavior of Materials at Semi-Solid State
Transactions of Materials Processing, volume 6, issue 4, 1997, Pages 319~328
A flow stress involving strain, solid fraction, and breakage ratio, and solid fraction updating algorithm were proposed to depict the deformation behavior of materials at the semi-solid state. In case of isothermally simple upsetting of Sn-15%Pb alloy at the semi-solid state, by comparing the results of finite element analysis with the existing experimental results, the reliability of both the developed flow stress and updating algorithm were investigated. It was found that the verified program can effectively be used in the rigid-viscoplastic finite element analysis of the semi-solid forging processes.
Process Design of Cold Forging for Automobile Air Conditioner Pulley using a Solid Billet
Transactions of Materials Processing, volume 6, issue 4, 1997, Pages 329~337
Forging of an inner pulley for compressor clutch assembly of car air conditioner is investigated in this study. In cold forging of inner pulley, the design requirements are to keep the same height of the inner rib and the outer one, and to make uniform the hardness distribution in the forged product. Using the rigid-plastic finite element simulation. we design the optimal process conditions, which has a performing operation. Also the final product configuration of forging has to be designed again in view of the metal flow involved in the operation, derived from the finite element simulations. The forged pulley is investigated by checking the hardness distribution and it is noted that the distribution has improved to be even and high enough for industrial application.
The Effect of Strain Rate on Macroscopic Behaviour in Compression Forming of Semi-Solid Aluminum Alloy
Transactions of Materials Processing, volume 6, issue 4, 1997, Pages 338~345
The behaviour of alloys in the semi-solid state strongly depends on the imposed stress stage and on the morphology of the phase which can vary from dendritic to globular. To optimal net shape forging of semi-solid materials, it is important to investigate for material behaviour for variation of strain rate. Therefore, to investigate the effect of compression speed on deformation of aluminum alloy with globular microstructure, the compression test for semi-solid aluminum alloy with controlled solid fraction is perform by material test system which is attracted with furance. The behavior of semi-solid aluminum alloy were discussed for the various solid fraction and die speed. The material constants in stress-strain were are also proposed.
Optimization Techniques of Die Disign on Hot Extrusion Process of Metal Matrix Composites
Transactions of Materials Processing, volume 6, issue 4, 1997, Pages 346~356
The fiber orientation distribution and interface bonding in hot extrusion process have an effect on the maechanical properties of metal matrix composites(MMC's). Aluminium alloy matrix composites reinforced with alumina short fibers are fabricated by compocasting method. MMC's billets are extruded at high temperature through conical and curved shaped dies with various extrusion ratios and temperature. This present study was directed to describe the systematic correlation between extrusion die shape and subsequent results such as fiber breakage, fiber orientation and tensile strength to hot extruded MMC's billet. Extrusion load, tensile strength and hardness for variation of extrusion ratios and temperature are investigated to examine mechanical properties of extruded MMC's SEM fractographs of tensile specimens are observed to analyze the fracture mechanism.