Initiation Criteria of High Explosives at different projectile or jet densities

Test results of initiation threshold values with tungsten spheres of different diameters d and Lexan spheres of 76 mm diameter can be very well described by the u 2 d‐Held‐criterion where u is the cratering velocity or \documentclass{article}\pagestyle{empty}\begin{document}$ {\rm v/(1 + }\sqrt {\varrho _{\rm t} /\varrho _{\rm p})} $\end{document} . For covered Composition B the initiation threshold value is 23 mm 3 /μs 2 . This value fits also shaped charge tests where the high explosive charge is also in a covered arrangement.