In order to quantitatively evaluate the overload stability of charge with defects, by adjusting the material and thickness of the waveform modulator, the waveform, amplitude, and pulse width of the loading signal were precisely controlled, based on the overload environmental force experimental device, the eigenvalues of charge load with different defects were measured, which can take into account the high overload pressure and wide pulse at the same time. The response degree of the charges under investigation was quantitatively characterized based on the burn marks, damage level, and mechanical fitting performance of the witness plates, grayscale numerical processing was applied to the surface images of the recovered witness plates after testing, the influence of the experimental system on the eigenvalues of charge load was quantified, and the correlation mechanism between charge response behavior and image grayscale was established. Based on clustering analysis, the primary stimulating factors affecting the stability of the charges, including defect diameter, flyer thickness, and the material and thickness of the waveform modulator, were classified, the corresponding conversion factors of the test device were introduced, the evaluation model of overload stability of defective charge was constructed, and the response critical pressure thresholds of different defective charges were predicted. The results indicate that the overload peak value greater than 1 GPa and high-impact pulse width greater than 100 μs can be achieved. With the increase of defect diameter, the response level of loading response increases significantly. The critical pressure of combustion reaction decreases from 0.71 GPa to 0.26 GPa with the increase of charge defect diameter from 0 mm to 12 mm. When the defect diameter of the charge reaches 10 mm, the critical pressure of deflagration reaction is 1.56 GPa. With the increase of defect diameter, the critical pressure of deflagration reaction decreases to 1.25 GPa when the defect is
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With the continuous improvement of the material performance requirements of the charged warheads, elucidating the microstructural evolution of nano-powders under shock loading becomes critical for optimizing damage-element materials. In this study, molecular dynamics simulations were employed to comparatively investigate the shock wave propagation characteristics, phase transition behavior, and dislocation evolution of typical Al-based nanostructured powders Al-Fe-Ni and Al-Fe. This study reveals the mechanisms of impact velocity and Ni element on the evolution of Al-based nanoparticles. The results indicate that increasing shock velocity significantly enhances the thermodynamic response of the materials and promotes phase transition. Fe and Ni particles exhibit minimal deformation at an impact velocity of 0.6 km/s. When the velocity was increased to 1.5 km/s, the pressure exceeds 35 GPa and the temperature surpasses 6000 K, resulting in the melting of Al particles and deep fusion of Fe and Ni particles. The thermodynamic coupling effects lead to the formation of a large number of other structures. Furthermore, shock velocity does not affect the spatial distribution of dislocations but significantly regulates dislocation density. The introduction of the Ni element enhances the thermodynamic response of the material, alters the evolution pathway of the body-centered cubic phase and increases the proportion of hexagonal close-packed structures. Moreover, Ni element introduction raises the dislocation density, adjusts the timing of dislocation reactions, and promotes the formation of sessile dislocations, dislocation pinning, and dislocation loop structures, thereby influencing the temporal evolution and spatial characteristics of dislocations. These findings provide a theoretical basis for optimizing the processing of damage-element materials and their application.
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