Effect of Triaxiality and Lode Angle on the Plasticity Behaviour of a Ti-6Al-4V Titanium Alloy

Abstract:

The widespread Von Mises plasticity model fails to take the hydrostatic and the Lode angle effects into account and the assumption of this model is not valid for all types of metallic alloys. Hence in the present work the applicability of the Von Mises plasticity model in applications on a Ti-6Al-4V Titanium alloy have been analysed. A virtual test methodology, combination of experiments and numerical analysis have been developed. For this purpose various tensile tests on different specimen shapes have been carried out experimentally. These tests have been subsequently numerically reproduced to calibrate a constitutive law which fits every single test best, highlighting the possible effect of triaxiality and Lode angle on plasticity (strain hardening behaviour). An analysis of the specimen fracture surfaces have been carried out to evaluate possible effect of triaxiality and Lode angle down to a microscopic level.

• Periodical: Key Engineering Materials (Volumes 577-578)
• Pages: 413-416
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.577-578.413
• Online since: September 2013
• Authors: Andrea Gilioli, Andrea Manes, Marco Giglio, Nima Allahverdizadeh
• Keywords: Lode Angle, Ti6Al4V, Titanium, Triaxiality, Virtual Test

References

[1] G.I. Taylor, H. Quinney, Philos Trans R Soc 230 (1931) 323.

[2] F. Yang, Q. Sun, W. Hu, Yield criterions of metal plasticity in different stress states, "Acta Metall. Sin."(Engl. Lett.)Vol.22 No.2 pp.123-130 Apr. (2009)

DOI: 10.1016/s1006-7191(08)60079-4

[3] Y. Bai, X. Teng, T. Wierzbicki, 2006b. Study on the effect of the third stress invariant on ductile fracture, report 151. Technical report, Impact and Crashworthiness Laboratory, Massachusetts Institute of Technology, Cambridge, MA

[4] M. Giglio, A. Manes, F. Viganò, Ductile fracture locus of Ti–6Al–4V titanium alloy, "International Journal of Mechanical Sciences", Vol. 54, Issue 1, January 2012, Pages 121–135

DOI: 10.1016/j.ijmecsci.2011.10.003

[5] M.Dunand, D.Mohr, Hybrid experimental-numerical analysis of basic ductile fracture experiments for sheet metals, "International journal of solids and structures", 2010, 47, pp.1130-1143

DOI: 10.1016/j.ijsolstr.2009.12.011

[6] Y.Bao, T.Wierzbicki, On fracture locus in the equivalent strain and stress triaxiality space, "International journal of mechanical sciences", 2004, 46, pp.81-98.

DOI: 10.1016/j.ijmecsci.2004.02.006

[7] A.M. Beese, M.Luo, Y.Li, Y.Bai, T. Wierzbicki, Partially coupled anisotropic fracture model for aluminum sheets, "Engineering Fracture Mechanics" 77 (2010) 1128–1152

DOI: 10.1016/j.engfracmech.2010.02.024

[8] M. Giglio, A. Manes, F. Viganò "Numerical simulation of the slant fracture of a helicopter's rotor hub with a ductile damage failure criteria "Fatigue and Fracture of Engineering Materials and Structures", Volume 35, Issue 4, pages 317–327, April (2012)

DOI: 10.1111/j.1460-2695.2011.01622.x