PSI - Issue 47

Marzak Zerouki et al. / Procedia Structural Integrity 47 (2023) 915–918

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Marzak Zerouki et al. / Structural Integrity Procedia 00 (2019) 000–000

1. Introduction The prediction of the behavior and failure of materials is a critical aspect of materials science and engineering. It involves understanding the response of materials to external mechanical and thermal loadings under environmental factors over time, see for instance Zerouki et al. (2020) and Gosh (2019). The aim is to ensure the reliability and safety of materials used in various applications. As such, the study of material behavior and failure prediction is an ongoing research area, with scientists and engineers developing new techniques and methods to improve the accuracy and reliability of their predictions. A bad prediction of the behavior and failure of materials can result in catastrophic consequences, such as accidents, equipment failures, and even loss of life. Therefore, modeling the behavior and failure of materials is an essential tool for enhancing safety, improving design and performance, reducing costs… Messelek et al. (2020), Roubache (2023), Benabou et al. (2020). In this work, the GTN (Gurson, Tvergaard, and Needleman) model is extended to incorporate shear mechanisms, viscous effects, and material anisotropy, Gurson (1977), Tvergaard and Needleman (1984), Ben Chabane et al. (2023). The extended model has been implemented into the Abaqus/Explicit and used to simulate tensile tests under different strain rates (10 -4 s -1 and 10 -3 s -1 ) and temperatures (25°C and 293°C). The comparison is made between numerical predictions and experimental results of specimens cut according to the three orthotropic directions 0°, 45°, and 90°. 2. Material and experimental method The material studied is an aluminum alloy AlMgMn (5045 series). It is presented in the form of a cold rolled sheet of 5 mm thickness. The chemical composition of the studied material was given in Table 1. These mechanical characteristics have been summarized in Table 2. Uniaxial tensile tests were carried out on specimens in the three rolling directions (0, 45, and 90°) at different strain rates and temperatures.

Table 1. Mass percentages of the alloying elements of the studied material. alloying elements Cu Mg Mn Si Ti Fe % 0.008 2.4 0.42 0.29 0.16 0.43 Table 2. Mechanical characteristics of the studied material and Lankford coefficient. Young's modulus E (MPA) Yield strength Re (MPa) Poisson coefficient r 69000 186 0.33 0.98

3. Experimental results The comparisons between the stress-strain curves, in the case of 25°C and 290°C with different strain rates, obtained according to the three directions of orthotropy with respect to the rolling direction were presented in Fig. 1. The results obtained reveal that the anisotropy is significantly manifested at high deformations, moreover the specimen cut at 90° registers an increase in the tensile strength compared to 0° and 45° in both cases. a b c d

Fig. 1. experimental results: a) 25°C and 10 -4 s -1 , a) 25°C and 10 -3 s -1 , a) 293°C and 10 -4 s -1 , a) 293°C and 10 -3 s -1 .