대한기계학회논문집A (Transactions of the Korean Society of Mechanical Engineers A)

  • 제38권8호
  • /
  • Pages.899-904
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  • 2014
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  • 1226-4873(pISSN)
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  • 2288-5226(eISSN)
대한기계학회 (The Korean Society of Mechanical Engineers)
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가스압력을 이용한 자유벌징에서 성형양 최대화를 위한 두께 분포 최적화

Study of Blank Thickness Optimization in Free Bulging for Maximizing Bulged Height

  • 유준태 (한국항공우주연구원 재료구조연구팀) ;
  • 윤종훈 (한국항공우주연구원 재료구조연구팀) ;
  • 이호성 (한국항공우주연구원 재료구조연구팀) ;
  • 윤성기 (한국과학기술원 기계공학과)
  • 투고 : 2014.04.15
  • 심사 : 2014.05.27
  • 발행 : 2014.08.01
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초록

자유벌징에 있어서 성형 높이를 최대화하기 위하여 블랭크의 두께 분포를 최적화 하였으며, 등가정하중을 이용한 구조최적화법을 사용하였다. 두께형상은 부드러운 곡선으로 나타내기 위하여 베지어곡선을 사용하였고 제어점의 위치가 설계변수이며, 최대 변형률을 일정 값으로 제한하였다. 사용된 소재는 인코넬 718 이며 최적화된 두께분포로 가공된 블랭크를 이용한 자유벌징 시험을 수행하여 평판형 블랭크를 사용한 결과보다 22% 더 높은 성형 높이를 얻었다. 최적화결과에서 예측된 변형형상, 정점에서의 변형 경향, 두께분포가 실험에서 얻은 결과와 유사하여 최적화 과정의 유효성을 입증하였고, 최적화 결과가 실제 구현될 수 있음을 검증하였다.

Thickness profiled blank is designed using optimization techniques for maximizing the bulged heights during the free bulging of Inconel 718. The thickness of the blank was described by the Bezier curve and the locations of the control points were used as the design variables for optimization. The maximization of the bulged heights within the limited strain range served as the objective function and constraints for optimization. The equivalent static loads method for non-linear static response structural optimization (ESLSO) was used and the result of the optimization revealed 22 increased bulged heights. A free bulging test using a blank with an optimized profile was conducted to verify the optimization process. The results were compared with those of numerical analysis in terms of bulged height and deformed shape.

키워드

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