Theoretical Model of Oblique Penetration of Rigid Projectiles into Concrete Targets at Attack Angles

To facilitate the pre-estimation of the trajectory and attitude of rigid projectiles obliquely penetrating into concrete targets at attack angles, an theoretical model of rigid projectiles obliquely penetrating into concrete targets at attack angles is proposed to predicate the influence of attack angle on the motion state of projectiles. This paper offers a new method for calculating the projectile load at the cratering stage by its surface stress distribution, and subdivides the cratering stage into the entering stage of the projectile nose and the remaining stage after the full entry as it is considered that the attack angle has most obvious effects at the cratering stage. Moreover, the influence of free surface effect and contact area change on the stress of the projectile body is considered in the cratering model. Then the tunnel and shear plugging model in the theoretical model of attitude deflection is used to predict the whole process of a rigid projectile obliquely penetrating into a concrete target at an attack angle. The computational results of the motion state of the projectile under different penetration situations are proved to be in good agreement with the experimental data. Moreover, the results show that at an oblique angle, the positive attack angle will aggravate the deflection and reduce the penetration ability, while the negative attack angle will inhibit the deflection and the penetration ability can be improved when the negative attack angle is in the right range. © 2023 China Ordnance Society. All rights reserved.