PSI - Issue 41

Alexander Inozemtsev et al. / Procedia Structural Integrity 41 (2022) 544–549 Author name / Structural Integrity Procedia 00 (2019) 000–000

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An important feature of the structure formation of localized shear bands after dynamic and static tests at the maximum levels of loading is the formation of crystalline domains with pronounced shear modes in the band structure. What is also important is the observation that in the regions, where the band structure is of , the localized shear crystalline domains often show obvious signs of polygonization. The size of polygons does not exceed 1-1.5 µm. In Figure 4 c,f, arrows point at polygons in localized shear bands. It should also be noted that in contrast to static test, the localized shear bands formed during dynamic tests at maximum levels of loading occur in narrow areas. Thus, during dynamic tests the width of the zone of plastic strain localization is 30-50 µm. Moreover, in the direction from the areas with geometric stress concentration 1 and 2, and 3 and 4 towards their central point of convergence, the width of the area, in which localization of plastic strain takes place, increases up to 50-70 microns. In static tests, the width of the zone of plastic strain localization is 100-140 microns. In this case, in the direction from areas with geometrical stress concentration 1 and 2, as well as 3 and 4 towards their central point of convergence, the width of the area, in which localization of plastic strain takes place, increases up to 250-300 microns and more. The arrows in Fig. 4 point at the structure areas, in which the processes of localization of plastic strain occurred under dynamic loading (Fig. 5a) and under static loading (Fig. 5b).

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Fig.5. The structure of AMg6 alloy after dynamic tests in the zone of shear band(a); the structure of AMg6 alloy after static tests in the zone of shear band (b)- х1 000. 4. Numerical calculation An approach for treating the medium with microdefects was developed by Bilalov D.A .at al. (2018) taking into account the nonlocality effect. A numerical simulation of the plastic strain localization under dynamic loading was carried out taking into account the nonlocality effect, Fig. 6. Conclusion The study of the process of plastic strain localization done by the infrared thermography method, structural studies made with the aid of a scanning electron microscope, the results of numerical simulation suggest that one of the mechanisms of plastic strain localization at the prescribed rates of loading in the AMg6 alloy is due to