The three-dimensional trajectory characteristics of the elliptical cross-section projectile into concrete target

Abstract

To gain a deeper understanding of the trajectory characteristics of oblique penetration of an elliptical cross-section projectile into concrete targets, a 3-D trajectory model for such a projectile was established. The wake-separation effect and cratering-effect were considered in the presented model. The 3-D trajectory model's accuracy and reliability were confirmed through oblique penetration tests. Lastly, the effects of various factors-including the ratio of the minor-axis and major-axis of the projectile cross-section (b), the asymmetry of the projectile cross-section (λ), the roll angle (ξ₀), the attack angle (γ₀), the sideslip angle (ψ₀) and the oblique angle of the XOZ plane (α₀)-on the trajectory of the elliptical section projectiles at oblique angles of the XOZ plane (β≠0°) were examined. Results indicate that, when the mass, the length, the length of projectile head and the cross-sectional area of the projectile and impact velocity are held constant, the trajectory stability of the major-axis side (ξ₀=0°) of the symmetrical elliptical cross-section (b₁=b₂) projectile is superior to that of the circular cross-section projectile, while the trajectory stability of the minor-axis side (ξ₀=90°) of the symmetrical elliptical cross-section projectile is inferior to that of the circular cross-section projectile at oblique angles of the XOZ plane. The range of γ₀ between 0° and +5° is conducive to enhancing trajectory stability of the symmetrical elliptical section projectiles at oblique angles of the XOZ plane. In the event that ψ₀ is not 0° or α₀ is not 0° or ξ₀ is neither 0° nor 90°, the symmetrical elliptical section projectile will be deflected in the YOZ, XOZ, and XOY planes at oblique angles of the XOZ plane. Especially, at range of the ξ₀ between 50° and 60°, the max Y-direction displacement attains a peak value. And the terminal attitude angle on the YOZ plane demonstrates a quadratic correlation with the α₀ and a linear correlation with the ψ₀.