Trajectory analysis of projectile obliquely penetrating into concrete target at attack angle

In order to analyze the influence of attack angle on the trajectory deflection, the trajectories of projectiles unnormally penetrating into concrete target at attack angle and oblique angle are predicted and compared. The trajectory model is based on three dimensional motion of rigid projectile, which is combined with modification of the free surface effect of concrete target. The deflection characteristics of trajectory at different impact velocities, the same oblique angle and different attack angles are analyzed and compared. The research results show that the negative attack angle may reduce the deflection of penetration trajectory, and the positive attack angle may enlarge its deflection. There exists initial negative attack angle which can minimize the trajectory deflection in oblique penetration case. It is also found that the attack angle shows approximate fluctuation and then back to zero during penetration, and the maximal attack angle is approximately linear with the initial attack angle.