Estimation of exit angle for oblique penetration using numerical analysis

Abstract

When a projectile impacts on the target obliquely, unlike the vertical impact, the moving direction of the projectile changes after the projectile perforates the target. In other words, there is a change between the incident angle and the exit angle of the projectile. The difference of two angles depends on several impact conditions: The material properties and the thickness of the target, the incident angle and the initial velocity of the projectile. In particular, the incident angle and the initial velocity of the projectile are the most important factors to determine the exit angle. Therefore, in this research, the effects of the incident angle and the initial velocity of the projectile on the exit angle were studied. For the aluminum and the steel targets, the exit angles were calculated using numerical analysis by changing the incident angle from 10 to 40 degrees, and the initial velocity from 200 to 350 m/s. The exit angles calculated by changing the incident at given initial velocity are fitted to an equation. This routine is repeated by changing the initial velocity. Using these equations, the exit angle at the given incident angle and the initial velocity can be obtained without any experiment or analysis. The result of this research can be applied to generate more accurate shot lines that represent deflection due to an oblique impact, which can produce more accurate the vulnerability assessment of the combat vehicle.