- 보스-리브 시험 시 마찰보정선도에 대한 펀치형상 및 유동응력의 영향
- ㆍ 저자명
- 윤여웅,강성훈,이영선,김병민,Yun. Y.W.,Kang. S.H.,Lee. Y.S.,Kim. B.M.
- ㆍ 간행물명
- 소성가공
- ㆍ 권/호정보
- 2009년|18권 8호|pp.640-645 (6 pages)
- ㆍ 발행정보
- 한국소성가공학회
- ㆍ 파일정보
- 정기간행물| PDF텍스트
- ㆍ 주제분야
- 기타
Recently, boss and rib test based on backward extrusion process was proposed to quantitatively evaluate the interfacial friction condition in bulk forming process. In this test, the tube-shaped punch with hole pressurizes the workpiece so that the boss and rib are formed along the hole and outer surface of the punch. It was experimentally and numerically revealed that the height of boss is higher than that of the rib under the severe friction condition. This work is focused on the effect of the punch design and flow stress on deformation pattern in boss and rib test. From the boss and rib test simulations, it was found that there is slight variation in both the heights of boss and rib according to the length of punch land, nose radius, and face angle. However the hole diameter of the punch and the clearance between the punch and die have a significant influence on the calibration curves showing the heights of the boss and rib. In addition, the effect of flow stress on the calibration curves was investigated through FE simulations. It was found that there is no effect of strength coefficient of the workpiece on the calibration curves for estimation of friction condition. On the other hand, the strain-hardening exponent of the workpiece has a significant influence on the calibration curve.