Three-phase 2D model of long-rod penetrating semi-infinite metal targets considering variation in nose shape

The nose shape effect on long-rod penetration was investigated by establishing numerical 2D models with different original nose shapes. The variations in nose shapes and the mass erosion rate of the rods in the transient phase, primary penetration phase, and secondary penetration phase were adequately analyzed by two dimensionless parameters, i.e., the nose shape factor N* and the diameter ratio of the rod nose and shank eta. In general, N*, eta and the mass erosion rate of the rod vary distinctly in different phases, i.e., unsteady in the initial transient and the secondary penetration phases, and quasi-steady in the primary penetration phase. Furthermore, a relationship between the mass erosion of the rod and the variation in the nose shape was established. A three-phase 2D model of long-rod penetration was further constructed by considering the variations in nose shape. This research may provide a reference to improve the theoretical model of long-rod penetration.