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Abstract: This paper presents the experimental design and results of an advanced set of reverse ballistic experiments with long gold rods, impacting SiC-N ceramics at impact velocities from 2.0 to 6.2km/s. Important issues for these experiments were the high accuracy and position requirements necessary to detect a possible failure wave or failure kinetics in SiC-ceramics as might be evidenced by a change in the slope of the penetration velocity–impact velocity curve. New and sophisticated evaluation methods were developed for this purpose and produced very reliable results. Analyses of the experimental results show clearly that there is no change in the slope of the penetration velocity–impact velocity curve, contrary to that inferred from previous data and analysis. [Copyright &y& Elsevier]

Abstract: This paper presents the experimental design and results for gold rod impact on DEDF (5.19g/cm3) and Borofloat (2.2g/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 (v p) in the range of v p=0.4–2.8km/s. As a consequence, the distance between the rod tip and the failure front is reduced with increasing . The Tate term R T increases with impact velocity. [Copyright &y& Elsevier]

Abstract: Reverse ballistic experiments were conducted using gold long rods impacting cylinders of silicon carbide to study the effect of failure kinetics in ceramic penetration. Some of the early experiments impacted off-centered due to the dynamics of the barrel and sabot. Nevertheless, the data appeared to be in good agreement with centered impact, although conventional wisdom suggested that penetration resistance should decrease due to lateral confinement effects. Numerical simulations of the experiments were conducted to investigate and to quantify the influence of lateral confinement as a function of impact velocity for the ceramic targets. Above 3.0km/s, close proximity to a lateral boundary results in less than a 2% increase in the penetration velocity. [Copyright &y& Elsevier]

Abstract: Previous work suggested the possibility that the effects of a failure wave, evidenced through a change in the slope of the penetration velocity vs. impact velocity (u–v p) curve resulting from an increase in target penetration resistance, could be observed in penetration experiments of SiC. However, the previous work had to combine two different sets of experimental data, one using long tungsten rods and the other copper shaped-charge jets. A new set of experiments was conducted to address the uncertainties associated with combining the two disparate data sets. Analysis of the new experiments showed no evidence of a distinct change in the slope of the u–v p response of SiC, up to an impact velocity of 6.2km/s. We re-examine the original data and analysis in light of the new experiments to understand the origins of the original misinterpretation. [Copyright &y& Elsevier]