Research On Deflection Characteristics Of Projectile Impacting Metal Plate

In modern ocean warfare,ballistic missiles play an increasingly important role.When a missile hits a target,there is a certain angle with the impact surface in most cases,which makes the attitude deflection of the missile occur in the process of penetration,and affects the hit accuracy of the missile.The research on the attitude deflection of the projectile in the process of non-ideal penetration into metal targets has become a hot spot.In this paper,by means of high-speed impact experiment and numerical simulation,aiming at the attitude deflection of a sharp-ogival-nose projectile in the course of non-ideal penetration into a metal target in the range of impact velocity from 400 to 800 m/s,the deflection mechanism of a harp-ogival-nose projectile in the course of oblique penetration,penetration with attack angle and joint penetration when the attack angle and oblique angle are in the same plane,and the effects of various factors on the deflection characteristics of the projectile are analyzed.The finite element model of projectile obliquity penetrating multi-layer metal target is established.In view of the trajectory deviation caused by the obliquity penetrating multi-layer metal target,the trajectory deviation of the target plate in the experiment is extracted and the damage morphology of the target plate is obtained.The results of the experiment and numerical simulation of two-stage light gas gun are compared and verified.The results show that the two are basically in agreement.The main control parameters of the projectile penetrating the metal target are analyzed,and the deflection mechanism of the projectile penetrating the metal target with oblique angle is studied,and the effects of various factors on the deflection characteristics of the projectile are analyzed.The results show that the main factors affecting the penetration of a projectile into a metal target are the nose shape of the projectile,the impact velocity,the impact oblique angle,the impact attack angle,the thickness of the target plate,the material of the projectile and the material of the target.During the penetration of a sharp ogival projectile into a metal target plate with an oblique angle,there exists a critical value of the impact velocity,when the velocity is lower than that value,the projectile deflects three times,and when the velocity is higher than that value,the projectile deflects twice;even if the impact angle is the same,the deflection direction of the projectile depends on the impact velocity.When the impact velocity is low,the projectile rotates counter-clockwise,and when the impact velocity is high,the projectile rotates clockwise.The deflection mechanism of projectile penetrating metal target with attack angle is studied,and the influence of various parameters on the deflection characteristics of projectile is analyzed.The results show that in the process of penetrating metal target,the existence of initial attack angle in the early stage of penetration results in uneven forces on the left and right sides of the projectile's head surface,which causes the first deflection of the projectile;the second deflection occurs when the projectile's tail is subjected to asymmetric contact force between the projectile and the target at the later stage of penetration;and when the attack angle is small,the angular velocity of the projectile's penetration after the target increases with the impact velocity.When the attack angle is large,the angular velocity of the projectile penetrating the target decreases with the increase of the impact velocity.When the attack angle and oblique angle are in the same plane,the deflection mechanism of projectile penetrating metal target with oblique angle and attack angle is studied,and the influence of various parameters on the deflection characteristics of projectile is analyzed.The results show that the projectile deflect three times during the joint penetration of metal target when the oblique angle and attack angle at same direction;the projectile deflect twice during the joint penetration of metal target when the oblique angle and attack angle at different direction;when the angle of attack is negative,the projectile after penetrating the target rotates clockwise;when the angle of attack is positive,the projectile after penetrating the target rotates counterclockwise.