- 국부적 변형 집중 저감을 통한 액압 성형성 개선연구
- ㆍ 저자명
- 신세계로,주병돈,문영훈,Shin. S.G.R.,Joo. B.D.,Moon. Y.H.
- ㆍ 간행물명
- 소성가공
- ㆍ 권/호정보
- 2014년|23권 5호|pp.317-322 (6 pages)
- ㆍ 발행정보
- 한국소성가공학회
- ㆍ 파일정보
- 정기간행물| PDF텍스트
- ㆍ 주제분야
- 기타
Bursting during tube hydroforming is preceded by localized necking. The retardation of the initiation of necking is a means to enhance hydroformability. Since high strain gradients occur at the necking sites, a decrease in local strain gradients is an effective way to retard the initiation of necking. In the current study, the expansion at potential necking sites was intentionally restricted in order to reduce the strain gradient at potential necking sites. From the strain distribution obtained from FEM, it is possible to determine strain concentrated zones, which are the potential necking sites. Prior to the hydroforming of a trailing arm, an incompressible material(such as lead) is attached to the tube where the strain-concentrated zone would contact the die. Due to the incompressibility of lead, the tube expansion is locally restricted, and the resultant strain extends to adjacent regions of the tube during hydroforming. After the first stage of hydroforming, the lead is removed from the tube, and the hydroforming continues to the final targeted shape without any local restriction. This method was successfully used to fabricate a complex shaped automotive trailing arm that had previously failed during traditional hydroforming fabrication.