Stress waves in concrete targets induced by hypervelocity projectile penetration: an experimental and numerical investigation

With the application of hypervelocity weapons in warfare, comprehensively evaluating their destructive effects is of particular interest for protective engineering. Existing studies mostly focused on the depth of penetration by hypervelocity projectile, while investigation on stress waves associated with hypervelocity penetration was very limited. To clarify the generation and propagation of stress waves in concrete targets induced by hypervelocity projectile penetration, in the present study, six spherical projectile penetration tests on concrete targets were firstly conducted with projectile velocity ranged from 1875 m/s to 3940 m/s, in which the stress waves were carefully measured by the PVDF transducers. Then corresponding numerical models were developed and validated, and based on the validated numerical model the mechanisms of generation and propagation of stress waves were clarified. It was found that the stress waves observed during hypervelocity penetration are generated by the continuous interactions of projectile and target during penetration, and have unique characteristics such as the directionality and the ''two peaks'' phenomenon when compared with the stress waves generated by charge explosion. Finally, the effects of projectile velocity, projectile material, and target strength on the stress waves below the penetration depth were numerically investigated, and two important indexes for evaluating the stress waves by hypervelocity penetration were proposed.