Skip to main content
Log in

Prediction of necking for two aluminum alloys under non-proportional loading by using an FE-based approach

  • Original Research
  • Published:
International Journal of Material Forming Aims and scope Submit manuscript

Abstract

Forming Limit Diagrams (FLDs) were found numerically for sheets under non-proportional loading by means of an FE-based Marciniak–Kuczynski (M-K) analysis. The material model used in the analysis includes two instability criteria; a non-local criterion to detect incipient localized necking and a through-thickness shear instability criterion. The objective was to study whether the effects of pre-straining on the FLD could be predicted by the chosen modeling approach, and compare the results from the two instability criteria. The results with the two criteria were different, but both criteria were able to capture the strong strain-path dependence of the FLDs as the governing phenomenon is plastic instability.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12
Fig. 13
Fig. 14
Fig. 15
Fig. 16
Fig. 17
Fig. 18
Fig. 19
Fig. 20

Similar content being viewed by others

Abbreviations

NLIC:

Non-local instability criterion

TTSIC:

Through-thickness shear instability criterion

RD:

Rolling direction

TD:

Transverse direction

WTM:

Weak texture model

ɛ x , ɛ y :

Logarithmic strains in the rolling and transverse direction

ɛ, ɛ e, ɛ p :

Strain tensor; total, elastic and plastic

σ :

Stress tensor

f :

Yield function

σ 0 :

Reference yield stress

R :

Strain hardening variable

Q i , C i :

Constants in Voce hardening rule

a, c, h, p, m :

Material constants in Yld89

R :

Strain ratio

\(r_\alpha \) :

Flow stress ratio

\(\sigma _\alpha \) :

Flow stress in α-direction

W p :

Specific plastic work

k :

Coefficient in the power-law hardening equation

n :

Exponent in the power-law hardening equation

n el :

number of elements in patch

t :

Thickness

CoV(t)σ t, t 0 :

Coefficient of variation, standard deviation and mean value of the thickness

\(\Delta \varepsilon _z^\Omega \) :

Non-local value of increment in thickness strain

τ :

Shear stress

σ 1, σ 2, σ 3 :

Principal stresses

φ :

Inclination of the localization band in the shear instability criterion

References

  1. Marciniak Z, Kuczynski K (1967) Limit strains in the process of stretch-forming sheet metal. Int J Mech Sci 9:600–620

    Article  Google Scholar 

  2. Graf A, Hosford WF (1990) Calculations of forming limit diagrams. Met Trans A 21A:87–894

    Article  Google Scholar 

  3. Samuel M (2004) Numerical and experimental investigations of forming limit diagrams in metal sheets. J Mater Process Technol 153–154:424–431

    Article  Google Scholar 

  4. Lademo O-G, Berstad T, Hopperstad OS, Pedersen KO (2004) A numerical tool for formability analysis of aluminium alloys. Part I: theory. Steel Grips 2:427–431

    Google Scholar 

  5. Lademo O-G, Pedersen KO, Berstad T, Hopperstad OS (2004) A numerical tool for formability analysis of aluminium alloys. Part II: experimental validation. Steel Grips 2:433–437

    Google Scholar 

  6. Abedrabbo N, Pourboghrat F, Carsley J (2006) Forming of aluminum alloys at elevated temperatures—part 2: numerical modeling and experimental verification. Int J Plast 22:342–373

    Article  MATH  Google Scholar 

  7. Butuc MC, Banabic D, Barata da Rocha A, Gracio JJ, Ferreira Duarte J, Jurco P, Comsa DS (2002) The performance of Yld96 and BBC2000 yield functions in forming limit prediction. J Mater Process Technol 125–126:281–286

    Article  Google Scholar 

  8. Wu PD, Jain M, Savoie J, MacEwen SR, Tugcu P, Neale KW (2003) Evaluation of anisotropic yield functions for aluminum sheets. Int J Plast 19:121–138

    Article  Google Scholar 

  9. Graf A, Hosford W (1993) Effect of Changing Strain Paths on Forming Limit Diagrams of Al 2008-T4. Met Trans A 24:2503–2512

    Article  Google Scholar 

  10. Graf A, Hosford W (1994) Influence of strain-path changes on forming limit diagrams of Al 6111 T4. Int J Mech Sci 36:897–8910

    Article  Google Scholar 

  11. Cao J, Yao H, Karafillis A, Boyce MC (2000) Prediction of localized thinning in sheet metal using a general anisotropic yield criterion. Int J Plast 16:1105–1129

    Article  MATH  Google Scholar 

  12. Karafillis A, Boyce M (1993) General anisotropic yield criterion using bounds and a transformation weighting tensor. J Mech Phys Solids 41:1859–11886

    Article  MATH  Google Scholar 

  13. Yao H, Cao J (2002) Prediction of forming limit curves using an anisotropic yield function with prestrain induced backstress. Int J Plast 18:1013–1038

    Article  MATH  Google Scholar 

  14. Chow CL, Yu LG, Tai WH, Demeri MY (2001) Prediction of forming limit diagrams for AL6111-T4 under non-proportional loading. Int J Mech Sci 43:471–486

    Article  MATH  Google Scholar 

  15. Stoughton TB (2000) General forming limit criterion for sheet metal forming. Int J Mech Sci 42:1–17

    Article  MATH  Google Scholar 

  16. Wu PD, Graf A, MacEwen SR, Lloyd DJ, Jain M, Neale KW (2005) On forming limit stress diagram analysis. Int J Solids Struct 42:2225–2241

    Article  Google Scholar 

  17. Yoshida K, Kuwabara T, Kuroda M (2007) Path-dependence of the forming limit stresses in a sheet metal. Int J Plast 23:361–384

    Article  MATH  Google Scholar 

  18. Bai Y, Wierzbicki T (2008) Forming severity concept for predicting sheet necking under complex loading histories. Int J Mech Sci 50:1012–1022

    Article  Google Scholar 

  19. Berstad T, Lademo O-G, Pedersen KO (2004) Formability modeling with LS-DYNA, 8th LS-DYNA International Users Conference. Detroit

  20. Berstad T, Hopperstad OS, Lademo O-G (2002) FLD calculator—a tool for calculation of foming limit diagrams with LS-DYNA, Report No. STF24 F02285 (Proprietary). SINTEF, Trondheim

  21. Kokkula S, Hopperstad OS, Lademo O-G, Berstad T, Langseth M (2006) Offset impact behaviour of bumper beam-longitudinal systems: numerical simulations. Int J Crashworthiness 11:317–336

    Article  Google Scholar 

  22. Lademo O-G, Berstad T, Eriksson M, Tryland T, Furu T, Hopperstad OS, Langseth M (2008) A model for process-based crash simulation. Int J Impact Eng 35:376–388

    Article  Google Scholar 

  23. Fyllingen Ø, Hopperstad OS, Lademo O-G, Langseth M (2008) Estimation of forming limit diagrams by use of the finite element method and Monte Carlo simulation. Comput Struct (in press). doi:10.1016/j.compstruc.2008.07.002

  24. Reyes A, Hopperstad OS, Lademo O-G, Langseth M (2006) Modeling of textured aluminum alloys used in a bumper system: material tests and characterization. Comput Mater Sci 37:246–268

    Article  Google Scholar 

  25. Bressan JD, Williams JA (1983) The use of a shear instability criterion to predict local necking in sheet metal deformation. Int J Mech Sci 25:155–168

    Article  MATH  Google Scholar 

  26. Hopperstad OS, Berstad T, Lademo O-G, Langseth M (2006) Shear instability criterion for plastic anisotropy, Report no STF80MK F06087. SINTEF, Trondheim

  27. Barlat F, Lian J (1989) Plastic behavior and stretchability of sheet metals. Part I: a yield function for orthotropic sheets under plane stress conditions. Int J Plast 5:51–66

    Article  Google Scholar 

  28. Belytchko T, Liu WK, Moran B (2000) Nonlinear finite elements for continua and structures. Wiley, Chichester

    Google Scholar 

  29. Lemaitre J, Chaboche J-L (1990) Mechanics of solid materials. Cambridge University Press, Cambridge

    MATH  Google Scholar 

  30. Lademo O-G (1999) Engineering models of elastoplasticity and fracture for aluminium alloys, Doctoral thesis. Norwegian University of Science and Technology, Trondheim

  31. Lademo O-G, Hopperstad OS, Langseth M (1999) An evaluation of yield criteria and flow rules for aluminum alloys. Int J Plast 15:191–1208

    Article  MATH  Google Scholar 

  32. Hooputra H, Gese H, Dell H, Werner H (2004) A comprehensive failure model for crashworthiness simulation of aluminium extrusions. Int J Crashworthiness 9:449–464

    Article  Google Scholar 

  33. Jain M, Allin J, Lloyd DJ (1999) Fracture limit prediction using ductile fracture criteria for forming of an automotive aluminum sheet. Int J Mech Sci 41:1273–1288

    Article  MATH  Google Scholar 

  34. Han HN, Kim K-H (2003) A ductile fracture criterion in sheet metal forming process. J Mater Process Technol 142:231–238

    Article  Google Scholar 

  35. Cockcroft MG, Latham DJ (1968) Ductility and the workability of metals. J Inst Met 96:33–39

    Google Scholar 

  36. Brunet M, Clerc P (2007) Two prediction methods for ductile sheet metal failure In: Cueto E, Chinesta F (eds), CP907, 10th ESAFORM Conference on Material Forming. American Institute of Physics

  37. Alsos HS, Hopperstad OS, Tornqvist R, Amdahl J (2008) Analytical and numerical analysis of sheet metal instability using a stress based criterion. Int J Solids Struct 45:2042–2055

    Article  Google Scholar 

  38. Hill R (1952) On discontinuous plastic states, with special reference to localized necking in thin sheets. J Mech Phys Solids 1:19–30

    Article  MathSciNet  Google Scholar 

  39. Hill R (1950) Mathematical theory of plasticity. Oxford University Press, Oxford

    MATH  Google Scholar 

  40. van Minh H, Sowerby R, Duncan JL (1974) Variability of forming limit curves. Int J Mech Sci 16:31–32

    Article  Google Scholar 

  41. Rojek J, Kleiber M, Piela A, Stocki R, Knabel J (2004) Deterministic and stochastic analysis of failure in sheet metal forming operations. Steel Grips 2:29–34

    Google Scholar 

  42. Pedersen K, Lademo O-G, Hopperstad OS (2004) Strain localisation in extruded sheets, Report No. STF80MK 05167 (Proprietary). SINTEF, Trondheim

Download references

Acknowledgements

The present work was carried out with financial support from the Faculty of Engineering Science and Technology, Norwegian University of Science and Technology (NTNU), the Research Council of Norway, Renault, Fondation Franco-Norvégienne, and Hydro Aluminium Structures.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to A. Reyes.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Reyes, A., Hopperstad, O.S., Berstad, T. et al. Prediction of necking for two aluminum alloys under non-proportional loading by using an FE-based approach. Int J Mater Form 1, 211–232 (2008). https://doi.org/10.1007/s12289-008-0384-6

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s12289-008-0384-6

Keywords

Navigation