High-Speed Deformation of Heterogeneous Environment. Taking into Account Stochasticity
Yu. I. Meshcheryakov, A. K. Divakov, G. V. Konovalov, N. I. Zhigacheva
Institute for Problems in Mechanical Engineering of the Russian Academy of Sciences, Saint-Petersburg, Russia
Keywords: velocity defect, velocity dispersion, shock wave attenuation, dynamic deformation instability
Abstract
Impact tests of 1565 aluminum alloy in the impactor velocity range of 242-653.7 m/s revealed that at a certain impactor velocity (626 m/s), a sharp increase in particle velocity occurs in localized regions of the target. Microstructural studies of the sample revealed traces of localized deformation. Simultaneously, material is ejected from the rear surface of the target. This phenomenon correlates with the stochastic behavior of strain carriers at the mesoscopic scale-the presence of mesoparticle velocity dispersion. To account for the influence of stochasticity on shock wave propagation, a system of equations from the continuum theory of dislocations is used, which includes a dislocation velocity distribution function. It is shown that local attenuation or acceleration of the shock wave is determined by the relationship between velocity dispersion and the flow velocity of the dislocations.
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