Modelling of shock waves in fcc and bcc metals using a combined continuum and dislocation kinetic approach

Model validation was performed by comparison of numerical results with experimental data for plate impact tests (uniaxial strain state) for aluminium (fcc), copper (fcc) and tantalum (bcc). The numerical results show that during the first 50ns after impact, the pre-cursor wave has an amplitude similar to the stress level behind the shock front and relaxes to HEL with time (wave propagation). The difference between the experimental and numerical values of the compared variables (longitudinal stress, pulse length, elastic precursor relaxation time) was within 5% for the fcc materials, with the similar accuracy obtained for the bcc material, particularly for loading in the principal material direction.