DIMENSIONALLY SCALED PENETRATION EXPERIMENTS TO EXTRACT PROJECTILE SIZES FROM SPACE EXPOSED SURFACES

impact experiments were conducted which employed soda-lime glass proje ctiles (50, 150, 1000 and 3175 mum in diameter; D(p)) and aluminum (11 00 series) and Teflon (FEP) targets of variable thickness (T; ranging from thick infinite halfspace targets P(p)/T < 0.11 to foil thicknesse s of a few microns P(p)/T > 100]). The objectives of these impact expe riments were to determine, at constant impact velocity, the relationsh ips 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 ta rget thickness. This relationship is described by polynomial fits whic h permit unique solutions for unknown projectile sizes (D(p)) from the measurement of T and D(h) on space-exposed surfaces.