High-Velocity Deformation of Heterogeneous Media: Incorporating Stochasticity

Impact testing of a 1565 aluminum alloy within an impactor velocity range of 242–653.7 m/s demonstrate that, upon reaching a specific impactor velocity (626 m/s), localized regions of the target exhibit a sharp increase in particle velocity. Microstructural analysis of the sample reveals evidence of localized deformation. Concurrently, material ejection from the rear surface of the target is observed. The discovered phenomenon correlates with the stochastic behavior of strain carriers at the mesoscopic scale; namely, the presence of mesoparticle velocity variance. To incorporate the influence of stochasticity on shock wave propagation, we employ a system of equations from the continuum theory of dislocations, into which a dislocation velocity distribution function is introduced. It is shown that the local attenuation or acceleration of a shock wave is determined by the relationship between the velocity variance and the dislocation flux velocity.