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Influence of specimen preparation, microstructure anisotropy, and residual stresses on stress–strain curves of rolled Al2024 T351 as derived from spherical indentation tests

Published online by Cambridge University Press:  31 January 2011

J. Heerens ,
F. Mubarok  and
N. Huber
J. Heerens*
Affiliation:
GKSS Research Centre Geesthacht, Institute of Materials Research, Materials Mechanics, 21502 Geesthacht, Germany
F. Mubarok
Affiliation:
GKSS Research Centre Geesthacht, Institute of Materials Research, Materials Mechanics, 21502 Geesthacht, Germany
N. Huber
Affiliation:
GKSS Research Centre Geesthacht, Institute of Materials Research, Materials Mechanics, 21502 Geesthacht, Germany
*
a) ddress all correspondence to this author. e-mail: juergen.heerens@gkss.de
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Abstract

In the present work, a previously developed neural network approach for analyzing spherical indentation experiments is applied to prestressed specimens to determine the effect of residual stresses on the identified stress–strain curves. Within this scope, a comparison to other measurement errors has been made, which are caused by surface preparation and anisotropy of the material. To validate the experimental and analysis approach, the effect of compressive and tensile prestresses was also simulated using a three-dimensional finite element model. The material investigated is a rolled 2024 T351, which is widely used for manufacturing airplanes. It is shown that the existing neural network approach is able to determine the stress–strain behavior in agreement with that obtained from tensile tests. The method is robust against most error sources, such as surface roughness, coarse grain structure, and anisotropy, if a sufficient number of experiments are available. The most important influencing factor can be the residual stress causing errors up to 20% in the identified stress–strain curves.

Keywords

AlHardnessStress/strain relationship
Type
Articles
Information
Journal of Materials Research , Volume 24 , Issue 3 , March 2009 , pp. 907 - 917
Copyright
Copyright © Materials Research Society 2009

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References

REFERENCES

1.Motarjemi, A., Kocak, M., and Ventzke, V.: Mechanical and fracture characterization of a bi-material steel plate. Int. J. Press. Vessels. Pip. 79, 181 (2002).CrossRefGoogle Scholar
2.Amancio, S.T., Sheikhi, S., dos Santos, J.F., and Bolfarini, C.: Preliminary study of the microstructure and mechanical properties of dissimilar friction stir welds in aircraft aluminium 2024-T351 and 6056-T4. J. Mater. Process. Technol. 206, 132 (2008).CrossRefGoogle Scholar
3.Ceyhan, U.: High Temperature Deformation and Fracture Assessment of Similar Steel Welds (Clausthal-Zellerfeld, Papierflieger, 2007). Available at: http://www.gbv.de/dms/clausthal/E_DISS/2007/db108543.pdf.Google Scholar
4.Field, J.S. and Swain, M.V.: Determining the mechanical properties of small volumes of material from sub micro indenter spherical indentations. J. Mater. Res. 10, 101 (1995).CrossRefGoogle Scholar
5.Taljat, B. and Zacharia, T.: New analytical procedure to determine stress-strain curve from spherical indentation data. Int. J. Solids Struct. 35(33), 4411 (1998).CrossRefGoogle Scholar
6.Kucharski, S. and Mroz, Z.: Identification of plastic hardening parameters of metals from spherical indentation tests. Mater. Sci. Eng. 318(1–2), 65 (2001).CrossRefGoogle Scholar
7.Kucharski, S. and Mroz, Z.: Identification of hardening parameters of metals from spherical indentation test., J. Eng. Mater. Technol. 123, 245 (2004).CrossRefGoogle Scholar
8.Zhao, M., Ogasawara, N., Chiba, N., and Chen, X.: A new approach to measure—Elastic-plastic properties of bulk materials using spherical indentation. Acta Mater. 54, 23 (2006).CrossRefGoogle Scholar
9.Cao, Y., Qian, X., and Huber, N.: Spherical indentation into elasto-plastic materials: Indentation-response based definitions of representative strain. Mater. Sci. Eng., A 454–455, 1 (2007).CrossRefGoogle Scholar
10.Chen, X., Ogahisa, N., Zaho, M., and Chiba, N.: On the uniqueness of measuring elastoplastic properties from indentation: The indistinguishable mysical materials. J. Mech. Phys. Solids 55(8), 1618 (2007).CrossRefGoogle Scholar
11.Huber, N. and Tsakmakis, Ch.: A new loading history for identification of viscoplastic properties by spherical indentation. J. Mater. Res. 19(1), 101 (2004).CrossRefGoogle Scholar
12.Tyulyukovskiy, E. and Huber, N.: Identification of viscoplastic material parameters from spherical indentation data: Part I. Neural networks. J. Mater. Res. 21(3), 664 (2006).CrossRefGoogle Scholar
13.Klötzer, D., Ullner, Ch., Tyulyukovskiy, E., and Huber, N.: Identification of viscoplastic material parameters from spherical indentation data: Part II. Experimental validation of the method. J. Mater. Res. 21(3), 677 (2006).CrossRefGoogle Scholar
14.Tyulyukovskiy, E. and Huber, N.: Neural networks for tip correction of spherical indentation curves from bulk metals and thin films. J. Mech. Phys. Solids 55, 391 (2007).CrossRefGoogle Scholar
15.Huber, N., Tyulyukovskiy, E., Schneider, H-C., Rolli, R., and Weick, M.: An indentation system for determination of viscoplastic stress-strain behaviour of small metal volumes before and after irradiation. J. Nucl. Mater. 377, 352 (2008).CrossRefGoogle Scholar
16.Sines, G. and Carlson, R.: Hardness measurements for determination of residual stresses. ASTM Bull. 180, 35 (1952).Google Scholar
17.Vitovec, F.H.: Stress and load dependence of microindentation hardness. ASTM Spec. Publ. 889, 175 (1985).Google Scholar
18.Tsui, T.Y., Oliver, W.C., and Pharr, G.M.: Influence of stress on the measurement of mechanical properties using nanoindentation: Part I. Experimental studies in an aluminium alloy. J. Mater. Res. 11(3), 752 (1996).CrossRefGoogle Scholar
19.Lepienski, C.M., Pharr, G.M., Park, Y.J., Watkins, T.R., Misra, A., and Zhang, X.: Factors limiting the measurement of residual stresses in thin films by nanoindentation. Thin Solid Films 447–448, 251 (2004).CrossRefGoogle Scholar
20.Swadener, J.G., Taljat, B., and Pharr, G.M.: Measurement of residual stress by load and depth-sensing indentation with spherical indenters. J. Mater. Res. 16, 2091 (2001).CrossRefGoogle Scholar
21.Underwood, J.H.: Residual stress measurement using surface displacement around an indentation. Exp. Mech. 30, 373 (1973).CrossRefGoogle Scholar
22.Suresh, S. and Giannakopoulos, A.E.: A new method for estimating residual stresses by instrumented sharp indentation. Acta Mater. 46(16), 5755 (1998).CrossRefGoogle Scholar
23.Carlsson, S. and Larsson, P. L.: On the determination of residual stress and strain fields by sharp indentation testing. Part I: Theoretical and numerical analysis. Acta Mater. 49 (12), 2179 (2001).CrossRefGoogle Scholar
24.Carlsson, S. and Larsson, P.L.: On the determination of residual stress and strain fields by sharp indentation testing. Part II: Experimental investigation. Acta Mater. 49 (12), 2193 (2001).CrossRefGoogle Scholar
25.Quan, G., Heerens, J., and Brocks, W.: Distribution of constituent particles in thick plate of Al-T351. Practical Metallogaphy 6, 304 (2004).CrossRefGoogle Scholar
26.Testing Machines and Systems for Metals (brochure). Available at: http://www.zwick.com/frame/Control.php?action=Frame,show&mainNavId=11.Google Scholar
27.Tyulyukovskiy, E.: Identification of mechanical properties of metallic materials from indentation tests. Ph.D. Thesis, FZKA-Report 7103, March (2005). Available at: http://bibliothek.fzk.de/zb/berichte/FZKA7103.pdf.Google Scholar
28.Huber, N. and Heerens, J.: On the effect of a general residual stress state on indentation and hardness testing. Acta Mater. 56, 6205 (2008).CrossRefGoogle Scholar
29.Kreysig, E.: Statistical Methods and Their Application (Vandenhoeck & Ruprecht, Göttingen, Germany, 1975).Google Scholar