AZ31 Magnesium Alloy Multiaxial LCF Behavior: Theory, Simulation and Experiments

Abstract:

In this work it is studied the low-cycle fatigue behavior of the magnesium alloy AZ31-B at several total strains under uniaxial and multiaxial cyclic loading conditions. Cyclic tests were carried out in a biaxial servo hydraulic machine under strain control at room temperature. Test specimens were machined in an hourglass shape from extruded rods. The total strain amplitudes started at 0,2% and ended at 1.4% regarding the von Mises equivalent strain. The particular mechanical behavior inherent to this type of materials, hexagonal closed pack microstructures, leads to conclude that it is necessary to have a numeric elastoplastic model based in experimental tests. In this paper is presented a numerical model based on stress-strain experimental data. The objective is to modulate several physical mechanisms inherent to the magnesium elastoplastic behavior. In order to validate the achieved model the numeric estimations were correlated with the experimental data and with the Jiang & Sehitoglu plasticity model. Results show that the implemented model modulation is in agreement with the experimental data. Some differences between the Jiang & Sehitoglu and the implemented model regarding the magnesium hysteresis loop modulation are pointed out.

• Periodical: Advanced Materials Research (Volumes 891-892)
• Pages: 1366-1371
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.891-892.1366
• Online since: March 2014
• Authors: Luís G. Reis*, Vitor Anes, Manuel de Freitas
• Keywords: Experiment, Fatigue, Magnesium Alloy, Plasticity, Simulation

References

[1] T. Naka, T. Uemori, R. Hino, M. Kohzu, K. Higashi, F. Yoshida, Effects of strain rate, temperature and sheet thickness on yield locus of AZ31 magnesium alloy sheet, Journal of Materials Processing Technology, 201 (2008) 395-400.

DOI: 10.1016/j.jmatprotec.2007.11.189

[2] J.H. Kim, D. Kim, Y. -S. Lee, M. -G. Lee, K. Chung, H.Y. Kim, R.H. Wagoner, A Temperature-Dependent Elasto-Plastic Constitutive Model for Magnesium Alloy AZ31 Sheets, International Journal of Plasticity, (2013).

DOI: 10.1016/j.ijplas.2013.04.001

[3] H. Wang, P.D. Wu, J. Wang, C.N. Tomé, A Crystal Plasticity Model for Hexagonal Close Packed (HCP) Crystals including Twinning and De-twinning Mechanisms, International Journal of Plasticity, (2013).

DOI: 10.1016/j.ijplas.2013.02.016

[4] H. Wang, P.D. Wu, J. Wang, Modeling inelastic behavior of magnesium alloys during cyclic loading-unloading, International Journal of Plasticity, (2013).

DOI: 10.1016/j.ijplas.2013.01.007

[5] D. Steglich, Y. Jeong, M.O. Andar, T. Kuwabara, Biaxial deformation behaviour of AZ31 magnesium alloy: Crystal-plasticity-based prediction and experimental validation, International Journal of Solids and Structures, (2012).

DOI: 10.1016/j.ijsolstr.2012.06.017

[6] J. Zhang, Q. Yu, Y. Jiang, Q. Li, An experimental study of cyclic deformation of extruded AZ61A magnesium alloy, International Journal of Plasticity, 27 (2011) 768-787.

DOI: 10.1016/j.ijplas.2010.09.004

[7] M. Li, X.Y. Lou, J.H. Kim, R.H. Wagoner, An efficient constitutive model for room-temperature, low-rate plasticity of annealed Mg AZ31B sheet, International Journal of Plasticity, 26 (2010) 820-858.

DOI: 10.1016/j.ijplas.2009.11.001

[8] J. Albinmousa, H. Jahed, S. Lambert, Cyclic behaviour of wrought magnesium alloy under multiaxial load, International Journal of Fatigue, 33 (2011) 1127-1139.

DOI: 10.1016/j.ijfatigue.2011.01.009

[9] J. Lévesque, K. Inal, K.W. Neale, R.K. Mishra, Numerical modeling of formability of extruded magnesium alloy tubes, International Journal of Plasticity, 26 (2010) 65-83.

DOI: 10.1016/j.ijplas.2009.05.001

[10] M.G. Lee, S.J. Kim, R.H. Wagoner, K. Chung, H.Y. Kim, Constitutive modeling for anisotropic/asymmetric hardening behavior of magnesium alloy sheets: Application to sheet springback, International Journal of Plasticity, 25 (2009) 70-104.

DOI: 10.1016/j.ijplas.2007.12.003

[11] Jiang, Y. and Kurath, P., 1996, A Theoretical Evaluation of the Incremental Plasticity Hardening Algorithms for Cyclic Nonproportional Loadings, ACTA Mechanica, Vol. 118, pp.213-234.

DOI: 10.1007/bf01410518

[12] Jiang, Y. and Sehitoglu, H., 1994, Multiaxial Cyclic Ratchetting under Multiple Step Loading, International Journal of Plasticity, Vol. 10, No. 8, pp.849-870.

DOI: 10.1016/0749-6419(94)90017-5

[13] Jiang, Y. and Kurath, P., 1996, Characteristics of the Armstrong-Frederick Type Plasticity Models, International Journal of Plasticity, Vol. 12, pp.387-415.

DOI: 10.1016/s0749-6419(96)00013-7