Issue 39

O. Daghfas et alii, Frattura ed Integrità Strutturale, 39 (2017) 263-273; DOI: 10.3221/IGF-ESIS.39.24 263 Experimental and numerical study on mechanical properties of aluminum alloy under uniaxial tensile test O. Daghfas, A. Znaidi, A. Ben Mohamed, R. Nasri University of Tunis Manar, National School of Engineers of Tunis, LR-MAI-ENIT BP37, 1002 Tunisie daghfasolfa@yahoo.fr , amna.znaidi@laposte.net , ahmed82enit@yahoo.fr , Rachid.nasri@enit.rnu.tn A BSTRACT . The main objective is to model the behavior of 7075 aluminum alloy and built an experimental database to identify the model parameters. The first part of the paper presents an experimental database on 7075 aluminum alloy. Thus, uniaxial tensile tests are carried in three loading directions relative to the rolling direction, knowing that the fatigue of aircraft structures is traditionally managed based on the assumption of uniaxial loads. From experimental database, the mechanical properties are extracted, particularly the various fractures owing to pronounced anisotropy relating to material. In second part, plastic anisotropy is then modeled using the identification strategy which depends on yield criteria, hardening law and evolution law. In third part, a comparison with experimental data shows that behavior model can successfully describe the anisotropy of the Lankford coefficient. K EYWORDS . Aluminum alloy; Experimental tensile test; Identification; Lankford coefficient; Mechanical properties. Citation: Daghfas, O., Znaidi, A., Ben Mohamed, A., Nasri, R., Experimental and numerical study on mechanical properties of aluminum alloy under uniaxial tensile test, Frattura ed Integrità Strutturale, 39 (2017) 263-273. Received: 04.11.2016 Accepted: 09.12.2016 Published: 01.01.2017 Copyright: © 2017 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. I NTRODUCTION he study of the behavior of metallic materials during the forming process is an important subject. The nature of the used materials and solicitations require a formulation taking into account elastoplastic behavior, finite deformation and the anisotropy of the material, in particular for thin sheet metal forming [ 1 ]. Despite the importance of the work in this field, aluminum alloys continue to be the center of interests of several researches in materials science. Their use in the automotive and aviation industry depends largely on their mechanical and thermal characteristics. The addition of zinc in aluminum does not alter the mechanical properties. Therefore metallurgists have turned to ternary aluminum-zinc-magnesium alloys (with or without copper) of the 7000 series that have been widely used as structural materials due to their attractive comprehensive properties, such as low density, high strength, ductility, toughness and resistance to fatigue [ 2 , 3] . The 7075 aluminum alloy (a typical Al–Zn–Mg–Cu alloy) is one of the most important engineering alloys. It is mainly used in the automotive industry, in transport and aeronautics due to its excellent strength/weight ratio [ 4] . These alloys have very good mechanical properties; it is the high-strength aluminum alloys with a low resistance to corrosion. The T