• Title/Summary/Keyword: Forming effects

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A Study of Forming limits of Transformation mode of AZ31 Alloy sheet (AZ31 합금 판재의 변형모드에 따른 성형한계에 관한 연구)

  • Jung, J.H.;Lee, Y.S.;Kwon, Y.N.;Lee, J.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2008.05a
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    • pp.378-382
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    • 2008
  • Since the sheet metal forming of Mg alloy is perform at elevated temperature, the effect of strain rates related with the forming temperature and forming speed and R-value is very important factor for formability and forming limits and deep drawing. It is investigated that the effect of material properties such as various temperature, forming speed and strain rates on formability and R-value of Mg alloy sheet in round cup deep drawing. Therefore, the investigation for process variables is necessary to improve formability and forming limits and deep drawing. Also, the effects of strain rate and drawbility were studied by the experiment. The temperature, forming speed, and strain rates and R-value are investigated. Forming of Mg alloy takes consider into temperature, proper forming speed and strain-rate and R-value the formed parts were good without defects for forming limits and deep drawing.

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A Study on Manufacture of Aluminum Automotive Piston by Thixoforging (반용융 단조 공정에 의한 자동차용 알루미늄 피스톤 제조에 관한 연구)

  • Choi, Jung-Il;Kim, Jae-Hun;Park, Joon-Hong;Kim, Young-Ho;Choi, Jae-Chan
    • Journal of the Korean Society for Precision Engineering
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    • v.23 no.1 s.178
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    • pp.136-144
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    • 2006
  • Aluminum engine piston is manufactured by thixoforging according to forming variables. It is very important to find effects of forming variables on final products in thixoferging. In order to find the effects, however, many researchers and industrial technicians have depended upon too many types of experiments. In this study, the process parameters which have influences on thixofurging process of aluminum automotive engine piston are found by a statistical method and the correlation equations between the process parameters and quality of product are approximated through the surface response analysis. Forming variables such as initial solid fraction, die temperature, and compression holding time are considered fur manufacturing aluminum engine piston by thixofurging. Hardness and microstructure are inspected so that optimal forming condition is found by the statistical approach.

Finite Element Analysis of Sheet Metal Forming Process Using Shell Element (쉘 요소를 이용한 박판성형공정의 유한요소해석)

  • Jung Dong-Won;Ko Hyung-Hoon;Lee Chan-Ho;You Ho-Young
    • Journal of the Korean Society for Precision Engineering
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    • v.23 no.1 s.178
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    • pp.152-158
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    • 2006
  • The AutoForm previously used the membrane element and it accomplished sheet metal forming analysis. The membrane analysis has been widely applied to various sheet metal forming processes because of its time effectiveness. However, it is well-known that the membrane analysis can not provide correct information for the processes which have considerable bending effects. In this research experimental results were compared with the analysis results obtained by using the shell element which is applied newly in the AutoForm commercial software. The shell element is a compromise element between continuum element and membrane element. The Finite element method by using shell element is the most efficient numerical method. From this research, it is known that FEA by using shell element can predict accurately the problems happened in actual experimental auto-body panel.

Effect of Cold Forming Method on Drawability Trunk Floor Panel (냉각성형공법이 트렁크 플로어 드로잉성에 미치는 영향)

  • 최치수;최이천;오영근;이정우;이항수
    • Transactions of Materials Processing
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    • v.10 no.2
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    • pp.123-129
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    • 2001
  • This study is to investigate the effects of cold forming method with steel sheet of SCP3C to improve continuous productivity. Experiments were carried out in various working conditions, such as the number of stamping and the punch temperature. The effects of the punch temperature and the number of stamping on drawability of steel sheet of SCP3C as well as clearance and draw-in in the number of stamping were examined and discussed. More improvement of continuous productivity in case of cold stamping rather than by conventional stamping at room temperature is obtained. The optimum forming condition for drawing trunk floor panel of SCP3C is shown as the punch is cooled by coolant of $-5^{\circ}C$ and at the same time both the die and the blankholder are heated by stamping and frictional heat.

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Effects of Blank Design factors on Stretch Flange Forming of the Tailored Blank Using Taguchi Method (다구찌법을 이용한 테일러드 블랭크의 신장플랜지 성형에 미치는 설계 인자의 영향 분석)

  • 백승엽;권재욱;이경돈
    • Transactions of Materials Processing
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    • v.9 no.4
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    • pp.339-347
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    • 2000
  • For the successful forming of tailored blank, it is important to control the deformation of the stretch flange mode, which is strong1y dependent upon the location of weld line and blank shape. In order to investigate the effects of tailored blank design factors on the stretch flange forming, we made the model die which can simulate stretch flange mode. Taguchi method was employed to analyze the sensitivity of blank design factors for the forming of tailored blank. From the results of experiment S/N ratios were calculated and using Variance Analysis, significance of parameters and optimal condition of each factors were extracted. Based on these analyses, the weld line height and the strength ratio and the arc center height were selected as effective parameter. The analysed result was practically applied for Side outer panel stamping process.

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Rigid-Plastic Finite Element Analysis of Anisotropic Sheet Metal Forming Processes by using Continuum Elements (연속체요소를 이용한 이방성 박판재료 성형공정의 강소성 유한요소해석)

  • 이동우;양동열
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 1997.10a
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    • pp.24-27
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    • 1997
  • In the present work, rigid-plastic continuum elements employing the shape change and anisotropic effects are derived for the purpose of applying more realistic blankholding force condition in three-dimensional finite element analysis of sheet metal forming process. In order to incorporate the effect of shape change effectively in the derivation of finite element equation using continuum element for sheet metal forming, the convected coordinate system is introduced, rendering the analysis more rigorous and accurate. The formulation is extended to cover the orthotropic material using Hill's quadratic yield function. For the purpose of applying more realistic blankholding force condition, distributed normal and associated frictional tangent forces are employed in the blankholder, which is pressed normal and associated frictional tangent forces are employed in the blankholder, which is pressed against the flange until the resultant contact force with the blank reaches the prescribed value. As an example of sheet metal forming process coupling the effect of planar anisotropy and that of blankholding boundary condition, circular cup deep drawing has been analyzed considering both effects together.

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Warm Incremental Forming with Local Heating Apparatus (국부가열장치를 이용한 온간 무금형 점진 성형)

  • Kim, S.W.;Lee, Y.S.;Kwon, Y.N.;Lee, J.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2008.10a
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    • pp.349-353
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    • 2008
  • A fundamental study on warm incremental forming of a magnesium alloy sheet has been carried out. In order to enhance the incremental formability of the magnesium alloy sheet, a local heating device was newly designed and manufactured. Through the incremental forming tests of AZ31 under various forming conditions, the effects of process parameters such as the temperature, feeding depth per cycle, and inclination angle on the incremental formability of AZ31 were investigated. In addition, conventional FLDs at elevated temperatures were constructed experimentally and applied to predict the forming failure.

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Forming Limits Diagram of AZ31 Alloy Sheet with the Deformation Mode (AZ31 합금 판재의 변형모드에 따른 성형한계에 관한 연구)

  • Jung, J.H.;Lee, Y.S.;Kwon, Y.N.;Lee, J.H.
    • Transactions of Materials Processing
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    • v.17 no.7
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    • pp.473-480
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    • 2008
  • Sheet metal forming of Mg alloy is usually performed at elevated temperature because of the low formability at room temperature. Therefore, strain rates affected with the forming temperature and speed must be considered as important factor about formability. Effects of process parameters such as various temperatures and forming speeds were investigated in circular cup deep drawing. From the experimental results, it is known that LDR (Limit Drawing Ratio) increase as the strain rate increase. On the contrary, the FLD (Forming Limit Diagram) shows lower value as faster strain rate. Therefore, anisotropy values are investigated according to the temperature and strain rates at each forming temperature. R-values also represent higher value as faster strain rate. It is known that the formability can be different with the deformation mode on warm forming of AZ31 alloy sheet.

Finite Element Analysis of Superplastic Forming Processes Considering Grain Growth (I) (결정립 성장을 고려한 초소성 성형공정의 유한요소해석(I))

  • Kim, Y.G.;Song, J.S.;Kim, Y.H.
    • Transactions of Materials Processing
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    • v.21 no.3
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    • pp.151-159
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    • 2012
  • Finite element simulations were conducted to investigate the influence of grain growth in the superplastic blow forming process. A microstructure-based constitutive model considering grain growth effects is proposed and used in the simulations. Also, a grain growth rate equation accounting for both static and dynamic grain growth is implemented. The simulations were made using a 2D plane-strain model for constrained blow forming and an axisymmetric model for free bulging. These two models showed different features during the forming stages. However, the forming pressure-time curve and the thickness distribution obtained by both simulations explained well the deformation hardening induced by the grain growth during superplastic forming. This study shows that grain growth is an important factor in determining the material behavior during superplastic deformation.

A Study on Warm Incremental Forming of AZ31 Alloy Sheet (AZ31 합금 판재의 온간 점진 성형에 관한 연구)

  • Kim, S.W.;Lee, Y.S.;Kwon, Y.N.;Lee, J.H.
    • Transactions of Materials Processing
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    • v.17 no.5
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    • pp.373-379
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    • 2008
  • A fundamental study on warm incremental forming of a magnesium alloy sheet has been carried out. In order to enhance the incremental formability of the magnesium alloy sheet, a local heating device was newly designed and manufactured. Through the incremental forming tests of AZ31 under various forming conditions, the effects of process parameters such as the temperature, feeding depth per cycle, and inclination angle on the incremental formability of AZ31 were investigated. In addition, conventional FLDs at elevated temperatures were constructed experimentally and applied to predict the forming failure.