Effect of obliquity on ricochet and cratering for hypervelocity impacts

摘要

Numerical simulations were used to investigate ricochet of a mild steel spherical projectile from an aluminum target as a function of impact obliquity for impact velocities of 3.0, 4.0, and 5.0 km/s. Impact obliquity was varied between 50° and 80° in nominally 5° increments, as measured from the normal to the target surface. The impact phenomenology is described and quantified. At these impact velocities, the projectile is highly fragmented from the impact. The mass and momentum of the ricocheted projectile debris, along with the ejection (ricochet) angle, were determined as a function of impact obliquity and velocity. Impact crater dimensions (diameters and depth of penetration) were also determined. It was found that ricochet of the projectile and cratering phenomenology changed dramatically at impact angles of ～70°, at which point the incoming projectile no longer effectively penetrates the target surface. It was also found that many results were independent of impact velocity for the range of velocities considered.