Numerical study of the transition from rigid to eroding-rod penetration

The behavior of rigid long rods, during deep penetration into thick metallic targets, is quite different from that of eroding rods. These differences are discussed in the present paper, through a series of 2D numerical simulations, compared with experimental data, on steel rods impacting aluminum targets. Special emphasis is placed on the threshold impact velocity, where the rods are starting to deform. At these velocities, penetration depths of the rods decrease substantially, and we were trying to account for these reductions in our simulations. We also study the effect of rod aspect ratio (L/D) on its penetration efficiency (P/L), as well as the role of rod and target strengths and their density ratio ($\rho_{\rm p}$/$\rho_{\rm t}$) on this efficiency