On a high-velocity annular impactor

Results of interaction of a high-velocity annular steel impactor with a flat steel plate are reported. An annular crater is formed on the frontal surface of the plate. On the backward surface of the plate, the material is spalled in the form of a solid quasi-disk whose diameter is almost twice the outer diameter of the annular impactor. This observations shows that annular impactors are more hazardous than solid impactors (with an identical velocity and outer diameter).