• 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.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2007년도 추계학술대회 논문집
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• pp.223-227
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• 2007

New forming technologies are being introduced to automotive manufacturing processes. 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 simultaneously manufactured by the process, while the conventional stamping demands the same number of die sets with the number of parts. In this study, the automotive rear floor side member was manufactured by the simultaneous forming. The position and the size of initial blank were determined by forming analyses and try-outs, and the blank movement during the forming was controlled by introducing the spotweld.

• 대한기계학회논문집A
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• 제27권8호
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• pp.1338-1346
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• 2003

Three-dimensional formability of the thermoplastic laminar composite was studied according to manufacturing conditions. Five different types of the plain weave fabric were used as reinforcement with PET matrix. The square blank was made by press consolidation technique and formed in the type hemisphere. B-factor defined as the ratio of width of yarn and distance between yarns was used as the factor of formability in the type of plain weave fabric. The formability of PET/Glass fabric laminar composite was estimated in terms of forming rate and B-factor with the thickness distribution, area ratio of blank, and intra-ply shear angle. The thickness distribution across hemisphere was strongly affected by the B-factor, forming rate and blank thickness. The area ratio of blank was increased with B-factor, forming rate and blank thickness. Also, it was found that the intra-ply shear angle depends on the B-factor and forming rate.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1998년도 제2회 박판성형심포지엄 논문집 박판성형기술의 현재와 미래
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• pp.95-101
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• 1998

The steel door inner was manufactured via a new route, tailored blanking process, to remove hinge reinforcement parts, using thicker panels laser welded, instead. It is very important, first of all, in this process, to design optimum configuration of tailored blanks and determine the optimum process control for the stamping. Generally, it was found that the severe deformation reduction behavior during stamping in the thinner panel around weld line caused cracks and the other troubles in formability. It is our purpose of this investigation to introduce how the process control parameters, such as tailored blank configuration, size, location in the die, the position of weld line, BHF, bead configuration, work on the formability. In addition, causes of cracks and movement of weld line after forming were analyzed and compared with computer simulation work.

• 한국자동차공학회논문집
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• 제10권2호
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• pp.174-185
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• 2002

The automotive industry faces many competitive challenges including weight and cost reduction to meet need for higher fuel economy. Tailored blanks offer the opportunity to decrease door weight, reduce manufacturing costs, and improve door stiffness. Optimization technology is applied to the inner panel of a door which is made by tailored blanks. The design of tailored blanks door starts from an existing door. At first, the hinge reinforcement and inner reinforcement are removed to use tailored blanks technology. The number of parts and the welding lines are determined from intuitions and the structural analysis results of the existing door. Size optimization is carried out to find thickness while the stiffness constraints are satisfied. The door hinge system is optimized using design of experiment approach. A commercial optimization software MSC/NASTRAN is utilized for the structural analysis and the optimization processes.

• 지질공학
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• 제20권3호
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• pp.257-269
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• 2010

본 연구에서는 급경사지재해 안정화기술 분야에 관하여 한국, 미국, 일본 및 유럽에서 출원 공개/등록된 특허를 중심으로 특허동향을 분석하였다. 중분류는 예측기술, 계측기술, 대책/보강/저감기술, 실내실험과 같이 4개로 분류하였으며, 2,134건의 최종 유효 분석대상 특허를 선별하였다. 특허건수와 출원인수의 상관관계를 이용한 포트폴리오 분석결과 한국 및 미국의 경우 발전기 단계에 있으며, 일본과 유럽의 경우 퇴조기에 있는 것으로 분석되었다. 한국의 경우 국가주도의 연구 활동으로 인하여 특허활동이 활발한 것으로 분석된다. 중분류 기술 분야별 분석 결과, 일본은 급경사재해 예측분야, 미국은 급경사재해 실내실험분야가 각 국가의 경쟁력 분야인 것으로 분석되었으며, 한국의 경우 급경사재해 예측과 급경사재해 실내실험 분야가 공백기술인 것으로 분석되었다. 분석결과를 토대로 기술별 향후 연구개발 방향을 정리하면 예측기술 분야에서는 신규 유한요소해석 방법 또는 수치해석 모델 정립이 필요하고, 계측기술 분야에서는 센서개발기술, 정보취합을 통한 재해예측기술, IT기술과 융합을 통한 장치관련 기술 등이 필요하다. 그리고 재해/대책/저감기술 분야에서는 기존 사방구조물의 개량, 차별화된 사면보강공법 등의 개발이 필요하며 실내실험분야에서는 새로운 최적화된 구조의 실험장치 또는 방법의 개발이 필요한 것으로 조사되었다.

• 소성∙가공
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• 제20권2호
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• pp.104-109
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• 2011

The metal front case of a mobile phone is manufactured by press forming and welding of thin metal sheets. Twisting of the frame after the forming process is one of main obstacle for the assembly with reinforcement by welding. This study introduces a method preventing twisting of the metal front case frame in press forming. The spring-back after forming produces twisting of the frame, which leads to a low structural stiffness. To reduce twisting, connectors are required to reinforce the structural stiffness of the frame. In this study, the twisting profile is evaluated using a finite element(FE) analysis for various connector shapes. The actual connector shape is determined by minimization of the frame twisting within the tolerance of the FE-analysis. To verify the validity of the proposed blank shape, a forming experiment is performed and the twisting profile is measured using a 3D laser scanning method. The dimensional accuracy is found to be within the tolerance and in good agreement with the FE-analysis.