PSI - Issue 59

Oleh Yasniy et al. / Procedia Structural Integrity 59 (2024) 271–278 Author name / Structural Integrity Procedia 00 (2023) 000 – 000

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characterized by jump-like deformation under uniaxial tension. The stress-strain diagram during uniaxial tension testing of composite material, specifically the AMg6 aluminum alloy, has been documented under soft loading conditions by Strizhalo and Vorob’ev (1993), (1997), and (1999), as well as by Fedak (2003). Different approaches are recognized for constructing the deformation diagrams of the AMg6 aluminum alloy. In particular, in the article by Yasnii et al. (2004) there was explored the jump-like deformation of the AMg6 alloy under tension, in addition, in the paper by Yasnii and Glad’o (2002) there was examined the impact of the cyclic tensile load component on the dislocation structure of the AMg6 alloy. In addition, the ANSYS software is widely used to predict jump-like deformation. In the paper by Yasniy et al. (2010), a methodology for modeling the structural inhomogeneity of a material using the finite element method was described. This approach conceptualizes the material as a composite comprising an elastoplastic matrix and brittle inclusions or dispersoids. The proposed finite element model effectively describes the discontinuous deformation observed in the Al-6%Mg alloy. It is known that artificial intelligence is constantly developing; therefore, in the presence of experimental data, it is expedient to use methods of machine learning to predict deformations. In particular, in the article by Javaheri et al. (2020), the deformation was analyzed using computer vision algorithms. The obtained data was used to train neural networks for estimating the mechanical properties of steel. In addition, in the paper by Yasniy et al. (2020), there was modeled the stress-strain diagram of AMg6 material based on the application of machine learning methods, in particular, by neural networks, boosted trees, support-vector machines, and k - nearest neighbors. In the article by Didych et al. (2022), jump-like creep using preliminary plastic strain was predicted, while in the article by Yasniy et al. (2023), methods of jump-like creep modeling of AMg6 aluminum alloy were compared. This study aims to use various methods to investigate and compare the jump-like deformation of AMg6 aluminum alloy during the tensile test in the soft loading mode.

Nomenclature  p (  i ) stress  s

stress of the beginning of the jumping process

stress increment

  e

strain increment between jumps

 (  i ) strain of the jump  n

increase in plastic deformation in the area of elastic-plastic deformation to  s

2. Analysis of the jump-like deformation of AMg6 aluminum alloy The jump-like deformation is accompanied by "steps" in the deformation diagram in a soft type of loading or a sawtooth form in a rigid type of tensile loading. The experimental basis for identifying the patterns of this process was experiments conducted by Yasnii et al. (2004). The studies were carried out at a loading rate of 1.6 MPa/s at a temperature of 293 K. The loading diagrams and the resulting deformation diagrams are shown in Fig. 1. When studying the material, it was found that this process is also accompanied by changes in the microstructure, which can be associated with jump-like increases in deformation. Analysis of the microstructure shows that there were destroyed and still continuous dispersoids in the AMg6 alloy due to uniaxial tension tests at a constant loading rate. Depending on the shape coefficient, their distribution is described by a dynamic stretch histogram based on the histogram of the number of dispersoids in the initial state (Fig. 2).