Penetration and failure of lead and borosilicate glass against rod impact

This paper presents the experimental design and results for gold rod impact on DEDF (5.19 g/cm3) and Borofloat (2.2 g/cm3) glass by visualizing simultaneously failure propagation in the glass with a high-speed camera and rod penetration with flash radiography. At a given impact velocity, the velocity of the failure front is significantly higher during early penetration than during steady-state penetration of the rod. For equal pressures but different stress states, the failure front velocities determined from Taylor tests or planar-impact tests are greater than those observed during steady-state rod penetration. The ratio of average failure front velocity to rod penetration velocity decreases with increasing impact velocity (vp) in the range of vp=0.4–2.8 km/s. As a consequence, the distance between the rod tip and the failure front is reduced with increasing image. The Tate term RT increases with impact velocity.