Investigation Of Influence Factors On The Resistance Performance Of Single-layer Metal Targets Against Foreign Object

The impact of foreign objects on aircraft or protective structures has become more and more important with the development of modern high-velocity research.Based on this,the2A12-T4 aluminum alloy target with the thickness of 6 mm is used as the research object.Through experiments and simulations,the influences of the initial oblique angles and the nose shapes of the projectiles on the penetration performance of the targets are studied.Major work includes the following parts:First of all,the experiments of aluminum alloy target plates impacted with high velocities by blunt-nosed projectiles were conducted using one-stage light gas gun.The influence of initial velocity of the projectiles on the target failure mode is analyzed,and ballistic limits of the projectile are obtained according to the initial-residual velocities of the projectiles fitted.The models of projectiles and targets are established with the J-C constitutive and failure relationship by using the ABAQUS finite element software,and the effectiveness of numerical simulation is verified by the ballistic limit of the projectile and failure form of the target.Secondly,the simulation models of the blunt-nosed projectile oblique impacting the aluminum alloy targets with small angle(0-10°)are established,and the anti-penetration performance of the targets under different oblique angles of the projectile is studied.It is found that the ballistic limit decreases with the increase of the initial oblique angle.In addition,the attitude change of the projectiles when penetrating the target has also been studied.It is found that the attitude of the projectile is related to its impact velocity and initial oblique angle.Moreover,the simulation models of projectile with different nose shape normal impacting the 6 mm thick plate and 2 mm thin plate are established and the influences of target thickness and nose shape of projectile on the resistance performance and failure mode of the target are studied.Analysis illustrates that when struck the thick plate,blunt-nosed projectile has the strongest penetrating performance,followed by the hemispherical-nosed and the ogival-nosed projectile.However,when struck the thin plate,ogival-nosed projectilehas the strongest penetrating performance,followed by the hemispherical-nosed projectile and the ogival-nosed projectile.When the thickness of target is around 2.5 mm,the blunt-nosed projectile and the ogival-nosed projectile have the same penetrating performance.Finally,the models of projectile with different nose shape oblique impacting 2 mm thin plate are established to study the influence of nose shape of projectile and initial oblique angle on the resistance performance and failure mode of the target.It is found that the penetrating performance of the blunt-nosed projectile decreases with the increase of the oblique angle.However,it is not obvious for the hemispherical-nosed projectile and ogival-nose projectile.