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

The Korean Society of Mechanical Engineers (대한기계학회)
권호 표지
DOI QR코드

DOI QR Code

A Theoretical Investigation of Forming Limits of Voided Anisotropic Sheet Metals

기공을 포함한 이방성 판재의 성형한계 예측

  • 유봉선 (한국기계연구원 재료연구부) ;
  • 임창동 (한국기계연구원 재료연구부) ;
  • 김영석 (경북대학교 기계공학부) ;
  • 원성연 (경북대학교 대학원 기계공학부)
  • Published : 2005.08.01
Download PDF
⟨ Previous Next ⟩

Abstract

Most failures of ductile materials in metal forming processes occurred due to material damage evolution - void nucleation, growth and coalescence. In this paper, the modified yield function of Liao et al in conjunction with the Hosford's yield criterion is studied to clarify the plastic deformation characteristic of voided anisotropic sheet metals. The void growth of an anisotropic sheet under biaxial tensile loading and damage effect of void growth on forming limits of sheet metals are investigated. Also the characteristic length defining the neck geometry is introduced in M-K model to incorporate the effect of triaxial stress in necked region on forming limits. The forming limits theoretically predicted are compared with experimental data. Satisfactory agreement was obtained between the predictions and experimental data.

Keywords

References

  1. Marciniak, Z. and Kuczynski, K., 1967, 'Limit Strains in the Process of Stretch-Forming Sheet Metal,' Int.J.Mech.Sci., Vol. 9, pp. 609-620 https://doi.org/10.1016/0020-7403(67)90066-5
  2. Gurson, A.L., 1977, 'Continuum Theory of Ductile Rupture by Void Nucleation and Growth: Part I - Yield Criteria and Flow Rules for Porous Ductile Materials,' J.Engng.Mater.Technol. ASME, Vol. 99, pp. 2-15 https://doi.org/10.1115/1.3443401
  3. Doege, E., Bagaviev, A. and Dohrmann, H., 1997, 'Formability Analysis Based on the Anisotropically Extended Gurson Model,' Advanced Methods in Materials Processing Defects, Ed. M.Predeleanu and P.Gilormini, pp. 281-288
  4. Liao, K-C., Pan, J. and Tang, S.C., 1997, 'Approximate Yield Criterion for Anisotropic Porous Ductile Sheet Metals,' Mech. Mater., Vol. 26, pp. 213-226 https://doi.org/10.1016/S0167-6636(97)00033-1
  5. Kim, Y.S., Won, S.Y. and Needleman, A., 2002, 'Prediction of Forming Limits for Anisotropic Sheet Metals Considering Void Growth,' Proc. Plasticity2002, Aruba, USA, pp. 409-410
  6. Needleman, A. and Tvergaard, V., 1977, 'Necking of Biaxially Stretched Elastic-Plastic Circular Plates,' J. Mech. Phys. Solids, Vol. 25, pp. 159-183 https://doi.org/10.1016/0022-5096(77)90021-7
  7. Hosford, W.F., 1979, 'On Yield Loci of Anisotropic Cubic Metals,' Proc. 7th North Am. Metalworking Conf., SME, Dearborn, MI, pp. 191-196
  8. Tadros, A.K. and Mellor, P.B., 1977, 'An Experimental Study of the In-Plane Stretching of Sheet Metal,' Int. J. Mech. Sci., Vol. 20, pp. 121-134 https://doi.org/10.1016/0020-7403(78)90073-5
  9. Kim, Y.S. 2001, 'Engineermg Plasticity,' Sigma Press
  10. Hu, J., Jonas, J.J. Zhou, Y. and Ishikawa, T., 1998, 'Influence of Damage and Texture Evolution on Limit Strain in Biaxially Stretched Aluminum Alloy Sheets,' Mat.Sci.Engng., Vol. A251, p. 243 https://doi.org/10.1016/S0921-5093(98)00585-1
  11. Bridgeman, P.W., 1952, 'Studies in Large Plastic Flow and Fracture,' McGraw Hill
  12. Kim, Y.S., Lee, Y.M., Won, S.Y. and Hwang, S.M., 2002, 'Effect of Material Damage on Forming Limits of Voided Anisotropic Sheet Metals,' Metal. Trans. A, Vol. 34A, pp. 1283-1290 https://doi.org/10.1007/s11661-003-0239-1
  13. Luo, Z.J., Ji, W.H, Guo, N.C., Xu, X.Y., Xu, Q.S. and Zhang, Y.Y., 1992, 'A Ductile-Damage Model and Its Application to Metal-Forming Processes,' J. Mat. Proc. Tech., Vol. 30, pp. 31-43 https://doi.org/10.1016/0924-0136(92)90037-S
  14. Son, H.S. and Kim, Y.S., 2001, 'Strain Path Dependence of Forming Limit Predicted by Barlat and Lians Non-Quadratic Anisotropic Yield Criterion for Sheet Metals,' Int. J. Korean Soc. Mech. Engng., Vol. 15(2), pp. 210-216
  15. Ragab, A.R. and Saleh, Ch.A,R., 2000, 'Effect of Void Growth on Predicting Forming Limit Strains for Planar Isotropic Sheet Metals,' Mech. Materials, Vol. 32, pp. 71-84 https://doi.org/10.1016/S0167-6636(99)00041-1
  16. Needleman, A. and Triantafyllidis, N., 1978, 'Void Growth and Local Necking in Biaxially Stretched Sheets,' J. Eng. Mater. Tech. Trans. ASME, Vol. 100, pp. 164-169 https://doi.org/10.1115/1.3443466
  17. Shi, M.F. and Gerdeen, J.C., 1991, 'Effect of Strain Gradient and Curvature of Forming Limit Diagrams for Anisotropic Sheets,' J. Mater. Shaping Technol., Vol. 9, pp. 253-268 https://doi.org/10.1007/BF02833650