SHAPED CHARGE JET PENETRATION INTO MASONRY MATERIALS

Experiments are presented where a shaped charge is fired into four masonry materials at standoff distances varying from 1.3 to 45 charge diameters. Some targets have been equipped with short circuit foils between individual blocks for recording the crater position as a function of time. In addition, jet residual velocities have been measured after perforating 5.5 CD thick walls. Time-distance data and jet residual velocities are analyzed with using the virtual origin concept and it is shown that a large part of the penetration process into masonry materials can be fairly reproduced by the hydrodynamic penetration law. It appears that at large standoff and unlike in RHA targets, the last part of the penetration process into such materials is characterized by a drop in the average cratering velocity. This effect could probably be related to after-flow effects and jet elements collisions with low strength crater walls.