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High strength 1565 aluminum alloy was tested within impact velocity range of 250-750
m/s in two schemes of shock loading: (i) under uniaxial strain conditions and (ii) in highvelocity penetration. The combination of load regimes allows the different stages of
multiscale structure formation to be retraced. The intensity of macro-meso momentum
exchange is found to be responsible for both resistance to spallation and high-velocity
penetration. The overall impact velocity region is found to be subdivided by three sub-regions
of different mechanisms of dynamic straining and scales. The strength behavior of material
differs for different regions of impact velocities. Within impact velocity regions where the
resistance to penetration increases, the spall strength decreases. The transition from one scale
level to another is shown to be realized through the excitation of velocity oscillations at the
mesoscale.
Keywords: aluminum alloy, spallation, high-velocity penetration, multiscale deformation, macro-meso momentum exchange, velocity oscillations |
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