Dimensionally scaled penetration experiments to extract projectile sizes from space exposed surfaces

Abstract

Impact experiments were conducted which employed soda-lime glass projectiles (50, 150, 1000 and 3175 μm in diameter; D p) and aluminum (1100 series) and Teflon (FEP) targets of variable thickness (T; ranging from thick infinite halfspace targets [D p/T < 0.1] to foil thicknesseof a few microns [D p/T > 100]). The objectives of these impact experiments were determine, at constant impact velocity, the relationships between the diameter of the resulting penetration hole (D h), the foil thickness (T) and the projectile size (D p). We found that D h, and other morphologic features such as rim structures in aluminum or spall phenomena in Teflon exhibit a systematic relationship to the target thickness. This relationship is described by polynomial fits which permit unique solutions for unknown projectile sizes (D p) from the measurement of T and D h on space-exposed surfaces.