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

The Korean Society of Mechanical Engineers (대한기계학회)
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Optimal Design of the Tractrix Die Used in the DDI Process for Manufacturing CG Pressure Vessels

CNG 압력용기 제작을 위한 D.D.I. 공정의 Tractrix 다이 최적설계

  • Lee, Kwang O (Dept. of Mechanical Engineering, Pusan Nat'l Univ.) ;
  • Sim, Hyeon Dae (Mechanical Convergence Technology, Pusan Nat'l Univ.) ;
  • Kwak, Hyo seo (Mechanical Convergence Technology, Pusan Nat'l Univ.) ;
  • Kim, Chul (Dept. of Mechanical Engineering, Pusan Nat'l Univ.)
  • 이광오 (부산대학교 기계기술연구원) ;
  • 심현대 (부산대학교 기계융합기술학과) ;
  • 곽효서 (부산대학교 기계융합기술학과) ;
  • 김철 (부산대학교 기계기술연구원)
  • Received : 2016.05.16
  • Accepted : 2016.08.12
  • Published : 2016.10.01
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Abstract

Tractrix dies, used in the deep drawing process, can be used to form CNG pressure vessels without a blank holder. Previous studies had only applied tractrix profiles to perform the first deep drawing process of DDI; but an optimal design of the tractrix die that focuses on improving die life and reducing production cost has not been performed yet. In this study, finite element analyses of deep drawing processes were conducted according to heights of the tractrix die by using translating asymptotes. In addition, researchers analyzed von-Mises stresses at the part of stress concentration of the die according to the forming punch loads in order to propose an optimal tractrix die design.

CNG 압력용기 제조를 위한 딥드로잉 공정에 사용되는 트랙트릭스 다이는 블랭크 홀더 없이 성형을 가능하게 한다. 기존의 연구에서는 D.D.I. 공정의 1차 딥드로잉 공정에 트랙트릭스 곡선을 다이에 적용하였을 뿐, 다이의 수명향상 및 제조원가 절감을 위한 형상 최적화에 관한 연구는 전무한 실정이다. 이에 본 논문에서는 트랙트릭스 곡선의 점근선 이동을 통하여 다이의 높이에 따른 딥드로잉 공정의 유한요소해석을 수행하였다. 또한 펀치의 성형하중에 따른 다이 응력집중부의 Von-Mises 응력을 분석하여 최적의 트랙트릭스 다이 형상을 제시하였다.

Keywords

References

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