Prediction of forming limit in stretch flanging by finite element simulation combined with ductile fracture criterion
Hirohiko Takuda1
, Takayuki Hama1, Kazuki Nishida1, Tohru Yoshida2, Jun Nitta2
1Department of Energy Science and Technology, Kyoto University, 606-8501 Kyoto, Japan.
2Steel Research Laboratories, Nippon Steel Corporation, 293-8511 Futtsu, Japan.
DOI:
https://doi.org/10.7494/cmms.2009.1.0219
Abstract:
In our previous studies, the limit strains of a few types of high-strength steel sheets under various strain paths from balanced biaxial to uniaxial tension were measured and compared with those derived from some criteria for ductile fracture. It turned out that the fracture strains derived from the criterion by Cockcroft and Latham gave the best fit to the experimental results. In this study, the criterion is applied to the prediction of forming limit in stretch flanging. The stretch flanging tests of a high-strength steel sheet are simulated by the dynamic explicit finite element program LS-DYNA ver. 971 with shell elements. The comparison of the simulated results with the experimental results shows that the forming limit in stretch flanging is successfully predictable by the present approach when the work hardening and damage of the sheet edge in the blanking process are taken into consideration.
Cite as:
Takuda, H., Hama, T., Nishida, K., & Yoshida, T. Nitta, J., (2009). Prediction of forming limit in stretch flanging by finite element simulation combined with ductile fracture criterion. Computer Methods in Materials Science, 9(1), 137 – 142. https://doi.org/10.7494/cmms.2009.1.0219
Article (PDF):
Keywords:
Sheet metal forming, Finite element method, Stretch flanging, Ductile fracture criterion
References:
Takuda, H., Mori, K., Fujimoto, H., Hatta, N., 1996, Prediction of Forming Limit in Deep Drawing of Fe/Al Laminated Composite Sheets Using Ductile Fracture Criterion, J. Mater. Process. Tech., 60, 291-296.
Takuda, H., Mori, K., Fujimoto, H., Hatta, N., 1999a, Prediction of Forming Limit in Bore-Expanding of Sheet Metals Using Ductile Fracture Criterion, J. Mater. Process. Tech., 92-93, 433-438.
Takuda, H., Mori, K., Hatta, N., 1999b, The Application of Some Criteria for Ductile Fracture to the Prediction of the Forming Limit of Sheet Metals, J. Mater. Process. Tech., 95, 116-121.
Takuda, H., Mori, K., Takakura, N., Yamaguchi, K., 2000, Finite Element Analysis of Limit Strains in Biaxial Stretching of Sheet Metals Allowing for Ductile Fracture, Int. J. Mech. Sci., 42, 785-798.
Takuda, H., Kanie, T., Isogai, E., Yoshida, T., 2004, Application of Ductile Fracture Criteria to Prediction of Forming Limit of High-Strength Steel Sheets, Steel Grips, 2, 439-443.
Takuda, H., Hama, T., Yoshida, T., Nitta, J., 2008, Forming Limit Prediction of High-Strength Steel Sheets in Stretch Forming, Steel Res. Intern., 79, Metal Forming 2008, 1, 19-23.
Marciniak, Z., Kuczynski, K., 1967, Limit Strain in the Processes of Stretch-Forming Sheet Metal, Int. J. Mech. Sci., 9, 609-620.
Cockcroft, M.G., Latham, D.J., 1968, Ductility and the Workability of Metals, J. Inst. Metals, 96, 33-39.
Hill, R., 1950, The Mathematical Theory of Plasticity, Oxford University Press, Oxford, 318-321.