• Title/Summary/Keyword: die face

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동서양 종교와 철학의 기초 - '죽음'의 문제를 바라보는 두 눈 -

  • Yu, Heun-U
    • Journal of the Daesoon Academy of Sciences
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    • v.16
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    • pp.69-85
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    • 2003
  • Death has been one of the basic objects in philosophy and religion. Why do people feel afraid about death? Maybe it is because they don't know the situation after death or because they have a wrong idea about it. Someone may think that he/she doesn't care the situation. But this attitude is wrong. We must understand that our attitude about life is shaped by our knowledge of the situation after death. A recurrent theme about death in popular thought is the idea that death is mysterious. As we have seen, it is difficult to formulate a satisfactory philosophical analysis of the concept of death. If it is impossible to analyse the concept of death, then it is impossible to explain precisely what we mean when we say that something dies. It might be said therefore that, in virtue of this fact, death is mysterious. Of course, death is not distinctively mysterious - all other unanalysable concepts are equally mysterious in this way. Reflection on death gives rise to a variety of philosophical questions. One of the deepest of these is a question about the nature of death. Typically, philosophers interpret this question as a call for an analysis or definition of the concept of death. Plato, for example, proposed to define death as the separation of soul from body. However, this definition is not acceptable to those who think that there are no souls. It is also unacceptable to anyone who thinks that plants and lower animals have no souls, but can nonetheless die. Others have defined death simply as the cessation of life. This too is problematic, since an organism that goes into suspended animation ceases to live, but may not actually die. The eastern philosophers proposed to define death as the nonduality of life and death. Taoists, for example, do not believe in the Wheel of Life of the Buddhists nor in the Heaven or Hell of Christianity. Taoists view existence as glorious. The whole Universe, they teach, is a marvelous, vibrant Unity wherein everything, visible and invisible, pulses with energy and changes. As being develops through the experience of existence, its vessels are swept onwards by the mighty stream of the eternal TAO to other forms of expression and activity. Man does not die; he merely extends into new fields. Taoists teach that the end of a person is the return to the Ultimate Reality. "Life is uncertain - Death is certain": This is a well known saying in Buddhism. Knowing very well that death is certain and it is a natural phenomenon that everyone has to face, we should not be afraid of death. Yet, instinctively, all of us fear death because we do not know how to think of its inevitability. We like to cling to our life and body and so develop too much craving and attachment.

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Effect of Punch Design and Friction Condition on Deformation Pattern in Boss and Rib Test (보스-리브 시험 시 펀치 형상 및 마찰 조건에 따른 변형 양상에 대한 연구)

  • Yun, Y.W.;Kang, S.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2009.10a
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    • pp.332-337
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    • 2009
  • Recently, boss and rib test based on backward extrusion process was proposed to quantitative evaluate the interfacial friction condition in bulk forming process. In this test, the tube-shaped punch with hole pressurizes the workpiece so that the boss and rib are formed along the hole and outer surface of the punch. It was experimentally and numerically revealed that the height of boss is higher than that of the rib under the severe friction condition. This work is focused on the effect of the punch design and friction condition on deformation pattern in boss and rib test. From the boss and rib test simulations, it was found that there is slight variation in both the heights of boss and rib according to the length of punch land, nose radius, and face angle. However the hole diameter of the punch and the clearance between the punch and die have a significant influence on the heights of the boss and rib. In addition, the effect of flow stress was also investigated on the deformation patterns through FE simulations.

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Application of the CAE Process to the Parameter Determination far the Tool Design of an Auto-body Member (자동차용 부재 금형설계의 공정변수 결정을 위한 CAE 프로세스 적용)

  • Kim Seho;Huh Hoon;Song Junghan
    • Transactions of the Korean Society of Automotive Engineers
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    • v.13 no.3
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    • pp.64-73
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    • 2005
  • This paper is concerned with the simulation-based parameter determination for the tool design in the stamping process of the complicated auto-body member. The CAE procedure of the stamping process is proposed so that troubles such as wrinkle, springback and excess metal be eliminated with changing parameters such as the blank size, the restraining force of the draw-bead and the embossing shape in the die face. The selected indicators of failure during forming are wrinkling. the amount of spring after unloading of the tool, the amount of excess metal developed .The proposed analysis scheme is applied to the tool and process parameter design for the front side member of a RV car. The simulation results show that the scheme can produce sound product from the viewpoint of thickness distribution, the contact condition between tools and the blank, the shape accuracy and so on.

Analysis of Drawbead Process by Static-Explicit Finite Element Method

  • Jung, Dong-Won
    • Journal of Mechanical Science and Technology
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    • v.16 no.12
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    • pp.1687-1692
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    • 2002
  • The problem analyzed here is a sheet metal forming process which requires a drawbead. The drawbead provides the sheet metal enough tension to be deformed plastically along the punch face and consequently, ensures a proper shape of final products by fixing the sheet to the die. Therefore, the optimum design of drawbead is indispensable in obtaining the desired formability. A static-explicit finite element analysis is carried out to provide a perspective tool for designing the drawbead. The finite element formulation is constructed from static equilibrium equation and takes into account the boundary condition that involves a proper contact condition. The deformation behavior of sheet material is formulated by the elastic-plastic constitutive equation. The finite element formulation has been solved based on an existing method that is called the static-explicit method. The main features of the static-explicit method are first that there is no convergence problem. Second, the problem of contact and friction is easily solved by application of very small time interval. During the analysis of drawbead processes, the strain distribution and the drawing force on drawbead can be analyzed. And the effects of bead shape and number of beads on sheet forming processes were investigated. The results of the static explicit analysis of drawbead processes show no convergence problem and comparatively accurate results even though severe high geometric and contact-friction nonlinearity. Moreover, the computational results of a static-explicit finite element analysis can supply very valuable information for designing the drawbead process in which the defects of final sheet product can be removed.

자유곡면 볼엔드 밀링공정에서 CUSP PATTERN 조정

  • 심충건;양민양
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.10a
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    • pp.106-110
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    • 2001
  • The ball-end milling process is widely used in the die/mold industries, and it is very suitable for the machining of free-form surfaces. However, this process is inherently inefficient process to compared with the end-milling or face milling process, since it relays upon the machining at the cutter/surface contact point. The machined part is the result of continuous point-to-point machining on the free-form surface. And cusps (or scallops) remain at the machined part along the cutter paths and they give the geometrical roughness of the workpiece. Thus, for the good geometrical roughness of the workpiece, it is required very tightly spaced cutter paths in this ball-endmilling process. However, with the tight cutter paths, the geometrical roughness of the workpiece is not regular on the workpiece since the cusp height is variable in the previously developed ISO-parametric or Cartesian machining methods. This paper suggests a method of tool path generation which makes the geometrical roughness of workpiece be constant through the machined surface. In this method, Ferguson Surface design Model is used and cusp height is derived from the instantaneous curvatures. And, to have constant cusp height, an increment of parameter u or v is estimated along the reference cutter path. In ball-end milling experiments, the cusp pattern was examined, and it was proved that the geometrical roughness could be regular by suggested tool path generation method.

Rectangular can backward extrusion analysis using FEM (FEM을 이용한 RECTANGULAR CAN 후방압출 해석)

  • 이상승;조규종
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.699-702
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    • 2001
  • The increasing demand in industry to produce rectangular cans at the reduction by the rectangular backward extrusion process involves better understanding of this process. In 2-D die deflection and dimensional variation of the component during extrusion, punch retraction, component injection and cooling was conducted using a coupled thermal-mechanical approach for the forward extrusion of aluminum alloy and low-carbon steel in tools of steel. Backward extrusion FE simulation and experimental simulation by physical modeling using wax as a model material have been performed. These simulations gave good results concerning the prediction of th flow modes and the corresponding surface expansions of the material occuring at the contact surface between the can and the punch. There prediction are the limits of the can height, depending on the reduction, the punch geometry, the workpiece material and the friction factor, in order to avoid the risk of damage caused by sticking of the workpiece material to the punch face. The influence of these different parameter on the distribution of the surface expansion along the inner can wall and bottom is already determined. This paper deals with the influence of the geometry changes of the forming tool and the work material in the rectangular backward using the 3-D finite element method.

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Effect of Punch Design and Flow Stress on Frictional Calibration Curve in Boss and Rib Test (보스-리브 시험 시 마찰보정선도에 대한 펀치형상 및 유동응력의 영향)

  • Yun, Y.W.;Kang, S.H.;Lee, Y.S.;Kim, B.M.
    • Transactions of Materials Processing
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    • v.18 no.8
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    • pp.640-645
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    • 2009
  • Recently, boss and rib test based on backward extrusion process was proposed to quantitatively evaluate the interfacial friction condition in bulk forming process. In this test, the tube-shaped punch with hole pressurizes the workpiece so that the boss and rib are formed along the hole and outer surface of the punch. It was experimentally and numerically revealed that the height of boss is higher than that of the rib under the severe friction condition. This work is focused on the effect of the punch design and flow stress on deformation pattern in boss and rib test. From the boss and rib test simulations, it was found that there is slight variation in both the heights of boss and rib according to the length of punch land, nose radius, and face angle. However the hole diameter of the punch and the clearance between the punch and die have a significant influence on the calibration curves showing the heights of the boss and rib. In addition, the effect of flow stress on the calibration curves was investigated through FE simulations. It was found that there is no effect of strength coefficient of the workpiece on the calibration curves for estimation of friction condition. On the other hand, the strain-hardening exponent of the workpiece has a significant influence on the calibration curve.

A Parametric Study of the Hemming Process by Finite Element Analysis (유한요소해석에 의한 헤밍 공정 변수연구)

  • Kim, Hyung-Jong;Choi, Won-Mog;Lim, Jae-Kyu;Park, Chun-Dal;Lee, Woo-Hong;Kim, Heon-Young
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.28 no.2
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    • pp.149-157
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    • 2004
  • Implicit finite element analysis of the flat surface-straight edge hemming process is performed by using a commercial code ABAQUS/Standard. Methods of finite element modeling for springback simulation and contact pair definition are discussed. An optimal mesh system is chosen through the error analysis that is based on the smoothing of discontinuity in the state variables. This study has focused on the investigation of the influence of process parameters in flanging, pre-hemming and main hemming on final hem quality, which can be defined by turn-down, warp and roll-in. The parameters adopted in this parametric study are flange length, flange angle, flanging die corner radius, face angle and insertion angle of pre-hemming punch, and over-stroke of pre-hemming and main hemming punches.

The Wear Prediction of $A1_{2}$$0_{3}$-TiC Series Ceramic Tool by Cutting Force Model (절삭력 모델에 의한 $A1_{2}$$0_{3}$-TiC계 세라믹 공구의 마멸 예측)

  • Kim, Jeong-Suk;Kang, Myeong-Chang;Jo, Jae-Sung
    • Journal of the Korean Society for Precision Engineering
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    • v.13 no.12
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    • pp.151-157
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    • 1996
  • The tool condition monitoring is one of the most important aspects to improve productivity and quality of workpiece. In this study, the wear of ceramic tool (A1$_{2}$0$_{3}$-TiC Series) cutting the hardened die material(SKD11) was investigated. Flank wear was more dominant than crater wear. Therefore the modeling of cutting force related to flank wear has been performed. The cutting force model was construct- ed by an assumption that the stress distribution on the tool face is affected by tool wear. The relationship between characteristics as cutting force and tool wear can be suggested by machining parameters depending on cutting conditions. Experiments were performed under the various cutting conditions to ensure the validity of force models. The theoretical predictions on the flank wear are approximately in good agreement with experimental results.

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A STUDY ON THE STRESS IN MOTHER OF AUTISTIC CHILDREN (자폐아동 어머니의 스트레스에 대한 연구)

  • Yoon, Soo-Young;Han, Kyung-Ja
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.4 no.1
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    • pp.54-67
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    • 1993
  • This study is to investigate the stress and stress degree in mothers of autistic children. In order to obtain data for planning nursing strategies for mothers of autistic children The assessment tool for the stress was constructed through reviewing literatures on the stress and gathering the stress items by nonstructed face to face interviewing 14 mothers of autistic children The stress tool consists of 74 items each with five point rating scale A data collection was made front 160 mothers of autistic children from 11 institutions for autistic children in Seoul and Kyung-Ki province. The reliability coefficients by Cronbach's a test was 0.94 for the stress scale. The results are as follows : 1) The mean of stress is 3.19, in the area of the etiology, prognosis and the treatment-education, with cause of the treatment the edeucatlon and the prognosis of child's handicap. The mean of stress is 2.85 In the area of the negative of mother's self image, 2.45 in the area of the mother's ordinary life. The mean of stress was 2.05, lowest in the family and social relationship 2) The mean score for the total was 2.62 points. The items with highest stress score were 'All autistic child has not been understood by the society', 'If we die, 1'm afraid that this child will not be cared by someone', 'There is no institution that the child get the schoolibg', etc The stress item with the lowest mean score were 'Keep away the child from husband', 'Being divorced by husband', etc. 3) An analysis of relationship of stress degree to general characteristic shows a statisically significants difference in the number of children in the family and the cognition of the seventy of the child problem

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