Taking the behavior of long-rod projectile vertically penetrating semi-infinite metal target as the subject, this paper deduces and reviews a series of modified penetration theories based on the hydro-dynamic theory of penetration (HTP). A large quantity of published experimental data and numerical simulation results are employed for discussion of the theoretical analysis results. The assumptions and premises for the establishment of HTP model are presented. Based on these experimental data, the numerical results and theoretical analysis results, the connotation, scope of application and limitation of HTP model are discussed. The nine application preconditions for the HTP model are proposed. If the strength of the target is taken into account, the Allen-Rogers model is available. On the basis of analysis of the Allen-Rogers model and considering the strength of the projectile, this paper developed a modified Allen-Rogers model, provided solutions for it and made comparative analysis. In view of the deceleration of the projectile in the process of penetration, the numerical simulation of the penetration was conducted. The derivation and evolution of the theoretical model from the modified Allen-Rogers model to Alekseevskii-Tate model are discussed.

penetration mechanics  /  penetration mechanism  /  hydrodynamics  /  long-rod projectile  /  hydro-dynamic theory of penetration