A theoretical investigation of the penetration properties of hollow particles

A novel investigation of the impact of hollow shaped charge jet particles on a steel target is made. The range of impact speeds considered is 2 to 8 km/s, the upper limit of which is greatly above the ranges considered in previous studies of such impacts. An Eulerian hydrocode developed within DERA is used. The code has been validated for this application by reproduction of previous work at lower impact speeds and by a large body of earlier work on shaped charges. Idealised particles having axisymmetric inner hollows and outer surfaces are considered. It is shown that the penetration achieved by a single individual hollow particle is much the same as that for a solid one of the same mass. However, we demonstrate the formation of a reverse jet travelling back through the hollow, analogous to the jets seen by earlier workers, but travelling much faster. This jet can cause significant disruption to the following particles. It is concluded that the presence of hollowness is likely to cause significant disruption to the penetration process in real jets.