• Journal of Ocean Engineering and Technology
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• v.12 no.1
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• pp.10-22
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• 1998

In the present work the elastic-plastic FE formulations using dynamic explicit time integration schemes are used for numerical analysis of a large auto-body panel stamping processes. For analyses of more complex cases with larger and more refined meshes, the explicit method is more time effective than implicit method, and has no convergency problem and has the robust nature of contact and friction algorithms while implicit method is widely used because of excellent accuracy and reliability. The elastic-plastic scheme is more reliable and rigorous while the rigid-plastic scheme require small computation time. In finite element simulation of auto-body panel stamping processes, the roobustness and stability of computation are important requirements since the computation time and convergency become major points of consideration besides the solution accuracy due to the complexity of geometry conditions. The performnce of the dynamic explicit algorithms are investigated by comparing the simulation results of formaing of complicate shaped autobody parts, such as a fuel tank and a rear hinge, with the experimental results. It has been shown that the proposed dynamic explicit elastic-plastic finite element method enables an effective computation for complicated auto-body panel stamping processes.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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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.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.24 no.6 s.177
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• pp.1499-1512
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• 2000

The dynamic explicit finite element method and the static implicit finite element method are applied effectively to analyze total auto-body panel stamping processes, which include the forming stage , the trimming stage and the spring-back stage.\The explicit time integration method has better merits in the forming stage including highly complicated three-dimensional contact conditions. On the contrary, the implicit time integration method is better for analyzing spring-back since the complicated contact conditions are removed and the computing time to get the final static state is short. In this work, brief descriptions of the formulation and the factor study are presented. Further, the simulated results for the total auto-body panel stamping processes are shown and discussed. The formability and the weld line movement in stamping with Tailor Welded Blanks were investigated through QTR-OTR-FRT.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4080-4086
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• 2010

In this study, a scanning fixture for flexible parts such as large automotive panels is developed. For the minimization of the weight deflection of a hood outer panel, the N-2-1 fixture principle for flexible parts is adopted in the fixture design. The designed fixture for a hood outer panel is fabricated using the Alufix system. The springback of the entire hood outer panel can be measured successfully by the laser scanning with the developed fixture, which verifies the usefulness of the proposed design method for the flexible panels.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.3 s.168
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• pp.78-85
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• 2005

The static implicit finite element method is applied effectively to analyze total roof panel stamping processes, which include the forming stage. complicated and abnormal Large size roof panel was analyzed by using commercial program called AutoForm. Analysis results examining possibility and validity of the AutoForm software and the factor study are presented. Further, the simulated results for the total roof panel stamping processes are shown and discussed. Its application is being increased especially in the automotive industrial area for the cost reduction, weight saving, and improvement of strength.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.3 no.4
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• pp.63-72
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• 2004

In this paper, a finite element formulation using dynamic-explicit time integration scheme is used for numerical analysis of auto-body panel stamping processes. The lumping scheme is employed for the diagonal mass matrix and dynamic explicit formulation. Auto-body panel forming is analyzed by using dynamic-explicit finite element method. Further, the simulated results of the auto-body panel stamping processes are shown and discussed. Its application is being increased especially in the stamping industrial area for the cost reduction, weight saving, and improvement of strength.

• Transactions of Materials Processing
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• v.14 no.8 s.80
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• pp.655-660
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• 2005

• 기계와재료
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• v.5 no.1 s.15
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• pp.84-93
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• 1993

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.10a
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• pp.57-62
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• 1992

박판 성형 공정에서는 복잡한 실제 차체판넬을 금형설계단계에서 빠르고 효율적으로 해석하기 위해 평면 변형 문제로 취급할 수 있는 많은 국부 단면들에 대해 단면 해석방법이 쓰이고 있다. 최근에 박박이론 및 굽힘 에너지가 보강된 박막 요소에 근거한 내연적 강소성 유한 요소 해석이 많이 연구되어 왔다. 본 연구에서는 박판 성형 공정의 단면 해석을 위해 외연적 강소성 유한 요소법을 사용하였고, 접촉처리는 직접적 시행착오법을 사용하였다. 또한 본 연구의 적합성을 보이기 위해 평면 변형을 가정한 실린더형 펀치 스트레칭과 트렁크 리드 대칭 단면을 해석하였다.

• Proceedings of the KAIS Fall Conference
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• 2007.05a
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• pp.28-31
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• 2007

자동차 측면충돌시 인체의 상해를 줄이기 위하여 도어 시스템 부품 중에 도어트림이 충격을 차단하고 인체를 보호하는 역할을 하고 있다. 차체 판넬이 변형되어 도어트림에 전달되는 충돌 에너지를 패드가 흡수 하는데 중대한 기능을 한다. 이전에 충격흡수 패드는 외곽부위의 수평면에 의존하여 설계되었으며 이 구조는 점진적으로 충격을 흡수 하는데 문제점이 발견 되었는데 트리즈의 6단계 창의성 기법을 적용하여 패드의 주요 특성을 찾아내고 그 특성에 모순을 해결하여 차종에 적용할 수 있는 기본 단면과 설계 자유도가 높은 충격흡수부재를 개발 하였다.