• 제목/요약/키워드: Initial blank

검색결과 117건 처리시간 0.024초

두께가 다른 두 용접관계 성형에 있어서 블랭크 설계 및 용접선 이동에 대한 유한요소법의 역추적 기법적용 (Application of the Backward Tracing Scheme of Finite Element Method for the Tailored Blank Design and Welding Line Movement in Sheet Metal Forming with Two Different Thickness)

  • 최환호
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 1999년도 춘계학술대회논문집
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    • pp.49-52
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    • 1999
  • Tailored-welded blanks are used for forming of automobile structural and skin components. Its main objective is to achieve weight and production cost reduction in manufacturing of the components. For successful application of tailored-welded blanks design of initial welded blanks and prediction of welding line movement are critical. Here the utilization of the backward tracing scheme of the finite element method shows to be desirable in design of initial welded blanks for net-shape production and in prediction of the welding line movement. First the design of initial blank in forming of welded thick sheet with isotropy is tried and it appears successful in obtaining a net-shape stamping product. Based in the first approach the backward tracing scheme is applied to anisotropic tailored blank. The welding line movement is also discussed.

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박판금속성형의 초기 블랭크 최적설계를 위한 삼차원 다단계 역해석 (Three dimensional multi-step inverse analysis for optimum design of initial blank in sheet metal forming)

  • 이충호;허훈
    • 대한기계학회논문집A
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    • 제21권12호
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    • pp.2055-2067
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    • 1997
  • Values of process parameters in sheet metal forming can be estimated by various one-step inverse methods. One-step inverse methods based on deformation theory, however, cause some amount of error. The amount of error is generally increased as the deformation path becomes more complex. As a remedy, a new three dimensional multi-step inverse method is introduced for optimum design of blank shapes and strain distributions from desired final shapes. The approach extends a one-step inverse method to a multi-step inverse method in order to reduce the amount of error. The algorithm developed is applied to square cup drawing to confirm its validity by demonstrating reasonably accurate numerical results. Rapid calculation with this algorithm enables easy determination of an initial blank of sheet metal forming.

고강도 강판 성형 공정의 스프링백 제어 (Springback Control in the Forming Processes for High-Strength Steel Sheets)

  • 양우열;이승열;금영탁;황진영;윤치상;신철수;조원석
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2003년도 제4회 박판성형 심포지엄
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    • pp.35-40
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    • 2003
  • In order to develope springback control technology for high-strength steel sheets, some studies have been conducted: dome stretching test, stepped s-rail forming and springback measurement, and optimally shaped initial blank design. First, to find out the formability of TRIP60, dome stretching test was performed. Next the stepped s-rail die, which was designed to form a channel type panel with large twist and wall curl, was manufactured and used to know the effect of controlling forming variables, such as blank holding force and flange amount on the springback. Furthermore, new measurement method of the springback was introduced to define wall curl and twist in geometrically complex panels. Finally, the optimally shaped initial blank was employed to verify one of the best ways to control the springback in channel type, high strength sheet panels.

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유한요소해석을 이용한 일체복합성형성에 대한 연구 (A Study On the Combined One Body Stamping Using F.E.A.)

  • 권승렬;이종길
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2005년도 춘계학술대회 논문집
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    • pp.171-175
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    • 2005
  • Automotive parts manufacturers are doing their best to strengthen the competitiveness. They are developing a large variety of new manufacturing technologies to reduce the manufacturing cost. Combined One Body Stamping(C.O.B.S) is one of the remarkable technologies to reduce production cost. C.O.B.S makes possible to form several parts together in a process using only one die set while conventional stamping demands the same number of die sets to the number of parts. But the deformation mechanism in C.O.B.S is more complicated because the interactions between blanks. So the interaction effects should be considered in the stage of initial blank shape design. In the study, a blank design method to consider the interactions between blanks was proposed and verified through the simulations and experiments. A commercial incremental FE code, LS-Dyna, was used to simulate the C.O.B.S Process. And a reverse one step FE code, Hyper Form, was used to predict initial blank shape. The boundary conditions of the reverse one step FE analysis were determined by the proposed method.

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자동차용 프론트 사이드 멤버의 일체복합성형해석 및 보강판재의 위치결정 (Determination of Position for Reinforcement Blank at Simultaneous Forming Analysis of Automotive Front Side Member)

  • 윤석진;김헌영;김관회;윤재정;송종호
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2008년도 추계학술대회 논문집
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    • pp.178-182
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    • 2008
  • Automotive manufacturers lay their eyes on the new manufacturing technologies because of the strengthened competition. Among them, a simultaneous forming is one of the innovative forming technologies to be able to reduce production time and cost. Several parts can be simultaneous manufactured by process, while the conventional stamping demands the same number of die sets with the number of parts. In this study, the automotive front side member was manufactured by the simultaneous forming. The position and the size of initial blank were determined by forming analysis and try-outs, and the blank movement during the forming was controlled by introducing the pilot pin.

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해석적인 방법을 이용한 복잡한 형상의 자동차 부재 스탬핑 공정에서의 주요 설계인자 연구 (Study on Design Parameters in a Stamping Process of an Automotive Member with the Simulation-based Approach)

  • 송정한;김세호;김승호;허훈
    • 소성∙가공
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    • 제14권1호
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    • pp.21-28
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    • 2005
  • This paper is concerned with the quantitative effect of design parameters on a stamped part of the auto-body. The considered parameters in this paper are the blank holding force, the draw-bead force, the blank size which greatly affect the metal flow during stamping. The indicators of formability selected in this paper are failures such as tearing, wrinkling and the amount of springback. The stamping process of the front side inner member is simulated using the finite element analysis changing the design parameters. The numerical results demonstrate that the blank holding force cannot control the local metal flow during forming although it controls the overall metal flow. The modification of the initial blank size considering the punch opening line ensures the local wrinkling and reduces the amount of springback after forming. The restraining force of draw-bead controls the metal flow in the local area and reduces the amount of excess metal. It is noted that the parametric study of design parameters such as blank holding force, the blank size and the draw-bead are very important in the process design of the complicated member.

유한요소법을 이용한 임의의 단면 딥드로잉 제품의 소재형상설계 (Blank Design for the General Shaped Deep Drawing Products by F.E.M)

  • 김상도;박민호;서대교
    • 소성∙가공
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    • 제4권4호
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    • pp.302-321
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    • 1995
  • A method of determining an optimum blank shape for the non-circular deep drawing process is investigated. The rigid-plastic finite element method is introduced and the computer program code is developed. The ideal shape of a drawn cup with uniform wall height is assumed and metal flow is traced back-ward step by step to predict an initial blank shape of the ideal cup. For examples of the non-circular deep drawing products, three cases of drawn cup with quadrilateral punch shape are considered and optimum blank shapes for each case are proposed and compared with experimental results.

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One-Step 이론을 이용한 차체판넬 성형 해석에 관한 연구 (Study of Forming Analysis Auto-body Panel Using One-step Theory)

  • 안현길;고형훈;이찬호;안병일;문원섭;정동원
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 춘계학술대회 논문집
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    • pp.585-588
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    • 2005
  • Many process parameters have an effect on the auto-body panel forming process. A well designed blank shape causes the material to flow smoothly, reduces the punch and yields a product with uniform thickness distribution. Therefore, the determination of an initial blank shape plays the important role of saving time and cost in the auto-body panel forming process. For these reasons, some approaches to estimate the initial blank shape have been implemented, in this paper The one-step approach using a finite element inverse method will be introduced to predict the optimal forming with changing of blank pressure the developed program is applied to auto-body panel forming.

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직접 격자 사상법을 이용한 직사각컵 및 S-Rail 성형공정의 3차원 유한요소 역해석 (Three Dimensional Finite Element Inverse Analysis of Rectangular Cup and S-Rail Forming Processes using a Direct Mesh Mapping Method)

  • 김승호;허훈
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 2001년도 추계학술대회 논문집
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    • pp.81-84
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    • 2001
  • An inverse finite element approach is employed for more capability to design the optimum blank shape from the desired final shape with small amount of computation time and effort. In some drawing or stamping simulation with inverse method, it is difficult to apply inverse scheme due to the large aspect ratio or steep vertical angle of inclination. The reason is that initial guesses are hard to make out with present method for those cases. In this paper, a direct mesh marring scheme to generate initial guess on the sliding constraint surface described by finite element patches is suggested for one step inverse analysis to calculate initial blank shape. Radial type mapping is adopted for the simulation of rectangular cup drawing process with large aspect ratio and parallel type mapping for the simulation of S-Rail forming process with steep vertical angle of inclination.

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접촉과 마찰을 고려한 바인더 랩의 유한 요소 해석 (Binder Wrap Analysis considering Gravity, Contact and Friction)

  • 유동진;이종민;전기찬
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 1996년도 자동차부품 제작기술의 진보
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    • pp.87-95
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    • 1996
  • The stamping process consists of two stages : First, the blank is held by the blank holder and then it is further formed into the die cavity by punch stroke. In actual stamping process, the accurate prediction of binder wrap is an indispensable step in sheet metal forming analysis because the initial plastic buckling induced by improper die design is directly related with fatal defect at the final stage. In the present work, an approach including the gravity effect of blank material and proper consideration of contact and friction is proposed. Computations are carried out for some actual auto-body parts using 3D FEM code to investigate the validity of the proposed methodology. Comparisons with experimental results show that the suggested scheme can be effectively applied to the precise prediction of binder wrap for arbitrarily curved die faces in which gravity and contact effect must be taken into account.