变截面弹体斜侵彻两层间隔钢靶弹道特性

The influence of the structural characteristics of variable cross-section projectile on the ballistic characteristics during obliquely penetrating the two-layer spaced steel targets is studied. The elliptical and variable cross-section projectiles obliquely penetrate a two-layer spaced steel target at an initial velocity of 1 020 m/ s and an impact angle of 5° in the experiments. The trajectories,velocities,deflection angles, longitudinal displacements and longitudinal accelerations of circular and elliptical equal cross-section projectiles,and circular-and elliptical-variable cross-section projectiles during obliquely penetrating the steel target are compared by numerical simulations,and the physical mechanism of which the structural characteristics of variable cross-sectional projectile affect the stability of its trajectory is revealed. The results indicate that,when the initial impact velocity of projectile is high,the cross-sectional area at the shoulder of projectile remains consistent,and the variable cross-sectional angle is within the range of 0° to 2. 5°,the velocity variations of projectiles with different cross-sectional shapes and variable cross-sectional angles during obliquely penetrating two-layer spaced steel targets are very small. For the variable cross-section projectile, a critical variable cross-section angle can be found by changing the structural characteristics of variable cross-section projectile, which makes the longitudinal displacement of the projectile penetrating the first-layer target plate basically zero. Different cross-sectional shapes of variable cross-sectional projectiles have different sensitivities to longitudinal motion and attitude deflection after penetrating the steel target at variable cross-sectional angles. The greater the ratio of long axis to minor axis of cross-sectional shape is,the greater the influence of variable cross-sectional angle on the deflection angular velocity is. Variable cross-section angle has an affect the force direction of the projectile during the process of penetrating the target,which may lead to the reversal of force on the projectile. The relevant studies have good guiding value for the optimization of structural characteristic parameters of variable cross-sectional projectile and the prediction of trajectory characteristics of variable cross-sectional projectiles during obliquely penetrating two-layer spaced steel targets.