PSI - Issue 79

Volodymyr Hutsaylyuk et al. / Procedia Structural Integrity 79 (2026) 501–507

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The mechanical properties of the material in the delivery state as provided in a manufacturer's certificate are presented in Table 2.

Table 2. Mechanical properties of the 2024-T3 aluminum alloy in the direction of rolling. MPa R m R 0.2 A, % 459 - 466 339 - 345 21,5 - 24,7

Fig. 1 The dimensions and shape of the samples used in the tests. Geometrical parameters of the sample was selected according to the capabilities and design of the experimental setup. The influence of additional load impulse was performed using a hydraulic machine ZD-100Pu equipped with a mechanical system to carry out additional load force impulse, as described by Chausov M. et al. (2004). Two loading configurations were applied: (1) Reference loading — monotonic tensile tests at room temperature with a constant crosshead displacement rate of 1 mm/min. (2) Combined loading — monotonic tension with a short force impulse applied at different positions of the stress–strain curve (in the elastic region and near the yield point). The impulse was generated by a modified universal testing machine equipped with a dynamic loading module, which provided an additional load of 50–170 kN over a short time interval (milliseconds). This configuration made it possible to study the influence of the impulse application time relative to the yield point on the evolution of deformation and fracture mechanisms. Extensometer with a base measuring 12.5 mm was used to measure the deformation. The test stand equipped with a computerized measuring system that allows the registration and recording of the results of measurements with a frequency of up to 2400 measurements per second. Additional load pulse was realized in the elastic and plastic deformation regions. Research realized according to the original method developed by authors. A detailed description of the methodology and test conditions was presented in an earlier article by Chausov M. et al. (2004). After fracture, specimens were examined using scanning electron microscopy (SEM) to analyse the fracture surface morphology and transmission electron microscopy (TEM) to reveal subgrain evolution, localized slip channels, and the formation of dissipative structures. The obtained methodology allowed us to evaluate how short-time impulse excitation affects the transition from elastic to plastic deformation, the redistribution of local strains, and the subsequent damage mechanisms under monotonic and cyclic loading. 3. Discussion and results Figure 2 presents the characteristic engineering stress–strain curves obtained for monotonic and combined loading of Aluminum 2024-T3 specimens. The application of a short force impulse near the yield point resulted in a noticeable increase in uniform elongation, while the ultimate tensile strength remained nearly unchanged. This effect was less pronounced when the impulse was applied earlier in the elastic region.