Influence of preliminary compressive deformation on the spall strength of aluminum single crystal

Spall strength is an important property of material subjected to the shock wave loading. It substantially depends on the initial microstructure and its evolution during the preliminary shock compression. By an example of aluminum single crystal, a number of random axisymmetric compressed states are examined by means of molecular dynamics (MD) simulations, different deformation modes are revealed and the spall strength is calculated during subsequent volumetric tensile tests. A domain of elastic states with the spall strength of about 9 GPa, plastically deformed (dislocation plasticity) states with the spall strength of 6-7 GPa and the states with BCC phase transformations and the spall strength in the range 6-9 GPa are revealed as the main scenarios depending on the combination of strains at preliminary compression. MD results are generalized by means of artificial neural networks (ANNs), which allow interpolation between MD-studied points and plotting of continuous dependencies.