结构变形对深侵彻弹体偏转的影响

Earth penetration weapon (EPW) is commonly used to attack the underground target. However, the ballistic trajectory deflection, which is essentially caused by the deflection of the penetrator, commonly decreases the penetration efficiency of the penetrator. Thus, both the deflection angle and depth of penetration (DOP) of the projectile demand rapid and precise predictions. Based on the differential-areal-force-law (DAFL) approach, an analytical contact-resistant pressure is applied on the projectile surface in simulation. It represents the resistant force of the target and considers the free-surface effects of all surfaces of a finite concrete target. The simulation model is verified by comparing with the test results of the DOP and rotation angle of projectiles in open references. The influence of structural deformation upon the deflection of the penetrator is investigated by comparing the dynamics and movement of rigid and deformable projectiles. It indicates that the structural deformation drives the deformable projectile to deflect, which changes the total moment and instant angular velocity of the projectile. Under the same impact conditions, the rotation angle of the deformable projectile is usually larger than that of the rigid projectile. With the aspect ratio of projectile and impact velocity of the projectile decreasing, and the oblique angle of the projectile increasing, the rotation angle of the rigid projectile increases. However, for the deformable projectile, with the aspect ratio and oblique angle of the projectile increasing and the thickness of the projectile decreasing, the rotation angle of projectile increases. The rotation angle of deformable projectile does not monotonously increase with the impact velocity of the projectile increasing. It should be analyzed according to its actual structural deformation. When the impact velocity is less than or equal to 800 m/s and the oblique angle of the projectile is larger than or equal to 20°, the higher the impact velocity, the larger the oblique angle and the aspect ratio, the thinner the thickness of the projectile, the structural deformation contributes larger deflection of the projectile. In this way, to promote the accuracy and reasonability of simulation, it is suggested that the projectile should be deformable when the deformation and dynamics of the projectile are demanded for non-ideal penetration of a penetrator.