Increasing needs for light weight and high safety in modern automobiles induced the wide application of high strength steels in automotive body structures. The main difficulty in the forming of sheet metal parts with high strength steel is the large amount of springback including sidewall curl and twist in channel shaped member parts. Among these shape defects, twist occurs frequently and requires numerous reworks on the dies compensate the shape deviation. But until now, it seems to be no effective method to reduce the twist in forming processes. In this study, a new forming process to reduce the twist deformation during the forming of automotive structural member was suggested. This method consists of forming and restriking of embosses on the sidewall around the stretch flanging area of the part. and was applied in the forming process design of an automotive front side inner member with high strength steel. To evaluate the effectiveness of the method, springback analysis using Pamstampa™ was done. Through the analysis results, the suggested method proven to be effective in twist reduction of channel shaped parts with stretch flanging area.

Abstract
 1. 서론
 2. 프론트 사이드 인너 멤버의 성형 공정
  2.1 부품 설계
  2.2 물성 시험
  2.3 성형 공정 설계
 3. 프론트 사이드 인너 멤버의 변형 특성
  3.1 성형 및 스프링백 해석
  3.2 비틀림 유발 요인
  3.3 모델 단순화 및 비틀림 평가
 4. 비틀림 저감 성형공정
  4.1 단순 모델에의 적용
  4.2 실 모델에의 적용
 5. 결론
 참고문헌

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