UNDERSTANDING BALLISTIC LIMIT SCALING LAWS

A series of critical perforation velocity experiments have been performed, where tungsten alloy spheres were shot at thin mild steel plates. The experiments were repeated at four geometric scales; with projectile diameters of 1.5, 3, 5, and 10 mm; and corresponding plate thicknesses of 0.872, 1.7, 2.9, 5.8 mm. It was found that the critical velocity for perforation decreased when the scale increased. The experimental results were replicated with multiple numerical simulation setups, and the simulation settings were adjusted in order to best replicate the decrease in critical velocity observed for larger scales. A simulation including a softer steel in the center of the target plate, which was softer in proportion to the measured cross-section Vickers Hardness of the corresponding experimental target, produced the best agreement with the experimental results.