Modelling of Forming Limit Strains of AA5083 Aluminium Sheets at Room and High Temperatures

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Abstract:

Present work analyses mathematical modelling to predict the onset of localized necking and rupture by shear in industrial processes of sheet metal forming of aluminium alloy 5083 such as biaxial stretching and deep drawing. Whereas the AA5083 sheet formability at room temperature is moderate, it increases significantly at high temperature. The Forming Limit Curve, FLC, which is an essential material parameter necessary to numerical simulations by FEM, of AA 5083 sheet was assessed experimentally by tensile and Nakajima testing performed at room and 400°C temperatures. Tensile test specimens at 0o, 45o and 90o to the direction of rolling (RD) and Nakazima type specimens at 0o RD of aluminium AA5083 were fabricated. Simple tensile tests at room and 400°C temperatures were performed to obtain the coefficients of plastic anisotropy and material strain and strain rate hardening behavior at different temperatures. Nakazima biaxial tests at room and high temperature, employing spherical punch were carried out to plot the limit strains in the negative and positive quadrant of the Map of Principal Surface Limit Strains, MPLS, of aluminium AA5083 sheet. The “Forming Map of Principal Surface Limit Strains”, MPLS, shows the experimental FLC which is the plot of principal true strains in the sheet metal surface (ε12), occurring at critical points obtained in laboratory formability tests or in the fabrication process of parts. Two types of undesirable rupture mechanisms can occur in sheet metal forming products: localized necking and rupture by induced shear stress. Therefore, two kinds of limit strain curves can be plotted in the forming map: the local necking limit curve FLC-N and the shear stress rupture limit curve FLC-S. Localized necking is theoretically anticipated to occur by two mathematical models: Marciniak-Kuczynski modelling, hereafter M-K approach, and D-Bressan modeling. Prediction of limit strains are presented and compared with the experimental FLC. The shear stress rupture criterion modeling by Bressan and Williams and M-K models are employed to predict the forming limit strain curves of AA5083 aluminium sheet at room and 400°C temperatures. As a result of analysis, a new concept of ductile rupture by shear stress and local necking are proposed. M-K model has good agreement with both D-Bressan models.

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January 2016

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[1] ASM Handbook, Aluminum and aluminium alloys. ASM International, p.675, (1993).

Google Scholar

[2] S. BRUSCHI, A. GHIOTTI and F. MICHIELETTO, Hot tensile behaviour of superplastic and commercial AA5083 sheets at high temperature and strain rate. Key Engineering Materials, vols. 554-557, pp.63-70, (2013).

DOI: 10.4028/www.scientific.net/kem.554-557.63

Google Scholar

[3] J.D. BRESSAN and F. BARLAT, A shear fracture criterion to predict limit strains in sheet metal forming. In: E. Ceretti, C. Giardini (Eds. ), ESAFORM 2010, Brescia, Italy, (2010).

DOI: 10.1007/s12289-010-0750-z

Google Scholar

[4] L. XU, F. BARLAT, D.C. AHN and J.D. BRESSAN, Forming limit and fracture mechanism of ferritic stainless steel sheets. Materials Science and Engineering A, 528, p.3113–3121, (2011).

DOI: 10.1016/j.msea.2011.01.011

Google Scholar

[5] J.D. BRESSAN and J.A. WILLIAMS, The Use of a Shear Instability Criterion to Predict Local Necking in Sheet Metal Deformation. Int. J. Mech. Sci., vol. 25, pp.155-168, (1983).

DOI: 10.1016/0020-7403(83)90089-9

Google Scholar

[6] R. HILL, Theoretical Plasticity of Textured Aggregates. Math. Proc. Cam. Phil. Soc., v. 85, pp.179-191, (1979).

DOI: 10.1017/s0305004100055596

Google Scholar

[7] J.D. BRESSAN and J.A. WILLIAMS, Limit Strains in the Sheet Forming of Strain and Strain-Rate Sensitive Materials, J. Mech. Working Tech., v. 11, p.291, (1985).

DOI: 10.1016/0378-3804(85)90003-8

Google Scholar

[8] J.D. BRESSAN, Material Plastic Properties Defects and the Formability of Sheet Metal. Advanced Methods in Materials Processing Defects, edited by M. Predeleanu and P. Gilormini, Elsevier, pp.273-280, (1997).

DOI: 10.1016/s0922-5382(97)80029-3

Google Scholar

[9] Z. MARCINIAK and K. KUCZYNSKI, Limit Strains in the Process of Stretch-Forming Sheet Metal. Int. J. Mech. Sci., vol. 9, pp.609-620, (1967).

Google Scholar

[10] M.C.S. FREITAS, L.P. MOREIRA and R.G. VELLOSO, Materials Research, vol. 16, 2013, pp.351-366.

Google Scholar

[11] G. FERRON, R., MAKKOUK and J. MORREALE, A parametric description of orthotropic plasticity in metal sheets, Int. J. Plasticity, vol. 10, 1994, pp.431-449.

DOI: 10.1016/0749-6419(94)90008-6

Google Scholar

[12] M. GANJIANI and A. ASSEMPOUR, Journal of Materials Engineering and Performance, vol. 17, 2008, pp.1-6.

Google Scholar

[13] W.H. PRESS, S.A. TEUKOLSKY, W.T. VETTERLING and B.P. FLANNERY, Numerical Recipes in Fortran 77, vol. 1, 2nd Ed., Cambridge University Press, Chapter 9, (1996).

DOI: 10.1086/416228

Google Scholar

[14] A. BARATA DA ROCHA, F. BARLAT and J.M. JALINIER, Materials Science Engineering, vol. 68, 1985, pp.151-164.

DOI: 10.1016/0025-5416(85)90404-5

Google Scholar

[15] P.F. BARIANI, S. BRUSCHI, A. GHIOTTI and F. MICHIELETTO, Hot Stamping of AA5083 Aluminium Alloy Sheets. CIRP Annals –Manufacturing Technology, vol. 62/1, pp.251-254, (2013).

DOI: 10.1016/j.cirp.2013.03.050

Google Scholar

[16] J.D. BRESSAN and R.K. UNFER, Experimental waviness evolution of Interstitial Free - IF steel sheet under biaxial stretching. Key Engineering Materials, vols 651-653, pp.102-107, (2015).

DOI: 10.4028/www.scientific.net/kem.651-653.102

Google Scholar