Issue 39

O. Daghfas et alii, Frattura ed Integrità Strutturale, 39 (2017) 263-273; DOI: 10.3221/IGF-ESIS.39.24 272 identification strategy. In this study, Barlat yield criterion with isotropic hardening is used. By comparing both experimentally measured and calculated data based on this criterion, it is demonstrated that this criterion leads to a good description of the phenomena. However, the Barlat criterion with isotropic hardening may be sufficient to correctly identify the behavior of the aluminum alloy in uniaxial test. The influence of the off-axis angle on anisotropy is studied. The results of simple tensile test were used subsequently to show the evolution of load surface for several tests. It is deduced that the best shaping in the design of the fuselage and the RADOM is realized using the 7075 alloy in the 45° direction. This direction allows us to have a good formatting with minimal fracture comparing with directions 0° and 90°. In Mechanical construction the shaping of materials requires good mechanical characteristic. It is seen that this type of alloy has the important mechanical strengths but low percentage elongation. In order to remedy tis disadvantage a succession of thermo-mechanical treatments will be applied to this commercial aluminum alloy. This latter point presents the topic of the next work. A CKNOWLEDGEMENTS would emphasize the help that I have had from the doctor Gahbiche Amen of the Mechanical Engineering laboratory (LGM) of the National school of Engineers El Monastir, where I carried out my present experimental studies in the course of this work. R EFERENCES [1] Kim, J.M., Yang, D. Y., Yoon, J. W, Barlat, F., The effect of plastic anisotropy on compressive instability in sheet metal forming, International Journal of Plasticity, 16 (2000) 649-676. [2] Yespica, W. J. P., Comparative study of the electrochemical behavior of 2024 -T351 and 7075-T7351 aluminum alloys neutral sodium sulfate middle, PhD thesis in Science at the Toulouse University, (2012). [3] Xiaobo , Y., Fatigue crack growth of alumina alloy 7075-T651 under non proportional mixed mode I and mode II loads, Frattura ed Integrità Strutturale, 38 (2016) 148-154. DOI: 10.3221/IGF-ESIS.38.20. [4] Williams, J.C., Starke, E.A., Progress in structural materials for aerospace systems, Acta Materialia, 51 (2003) 5775– 5799. [5] Dursun, T., Soutis, C., Recent developments in advanced aircraft aluminium alloys, Materials and Design, 56 (2015) 862–871. [6] Ben Mohamed, A., Znaidi, A., Baganna, M., Nasri, R.., The Study of the Hardening Precipitates and the Kinetic Precipitation. Its Influence on the Mechanical Behavior of 2024 and 7075 Aluminum Alloys Used in Aeronautics, Springer, 2 (2014) 219–228. [7] Lee, N.S., Chen, J.H, Kao, P.W., Chang, L.W., Tseng, T.Y., Su J.R., Anisotropic tensile ductility of cold-rolled and annealed aluminum alloy sheet and the beneficial effect of post-anneal rolling, Scripta Materialia , 60 (2009) 340–343. [8] Ben Mohamed, A., Znaidi, A., Daghfas, O., Nasri, R., Evolution of mechanical behavior of aluminum alloy al 7075 during the time of maturation, International journal of technology, 6 (2016) 1076-1084. [9] Dogui, A., Anisotropic plasticity in large deformation, Ph.D thesis of sciences, University Claude Bernard-Lyon I, (1989). [10] Boumaiza, A., Influence of structural anisotropy of the plastic behavior during deformation by stamping, Ph.D thesis of sciences at the University Mentouri, Constantine, (2008). [11] Tajally, M., Emadoddin, E., Mechanical and anisotropic behaviors of 7075 aluminum alloy sheets, Materials and Design , (2010). DOI:10.1016/j.matdes.2010.09.001. [12] Barlat, F., Lege, D.J., Brem, J.C., A six-component yield function for anisotropic materials, International. Journal of Plasticity, 7 (1991) 693–712. [13] Barralis, J., Maeder, G., Specific- Metallurgy- Development, Structures, Properties Normalization AFNOR, NATHAN, (1995). [14] Develay, R., Properties of aluminum and aluminum alloys, Technical Engineer, M440 (1990). [15] French Norm NF A 03-151, Tensile test, French Association for Standardization AFNOR, (1971). I