An engineering impact model for yawed projectiles

When a long-rod projectile penetrates a thick target with an angle of attack, interfering of the projectile with the sidewall of a crater is the mechanism for the degraded penetration performance. By using an engineering model, significant parameters and how they vary over a wide velocity range can be quickly obtained. A transient discreet impact model is developed to predict not only the crater profile but final depth generated by the penetration of a yawed long rod. The yawed long rod is described as a series of continuous finite disk elements which enables us to keep revising the time-dependent crater profile. To consider the interaction with the crater sidewall, effective diameters for each element are used, and the revised crater profile is calculated based on these effective diameters. Three possibilities of the degree of degradation in penetration for the elements that interact with crater sidewall are discussed. The model reduces, in the case of the impact with no yaw, to the Alekseevskii–Tateʹs solution. Theoretical predictions are compared with the corresponding experimental data.