月牙形空腔结构金属靶的抗弹性能分析

On ballistic performance of a metal target with crescent-shaped cavity structure

为提高金属靶的抗弹性能,设计了一种含有月牙形空腔结构的金属靶。利用ABAQUS软件对月牙形空腔结构在12.7 mm穿甲燃烧弹弹芯侵彻下的弹体偏转性能进行了数值模拟研究,讨论了月牙形状、弹着点和空间排布对弹体偏转效果的影响。结果表明:月牙形状对弹体的偏转效果有显著的影响;空腔结构在不同弹着点表现出不同的弹体偏转性能,处于空腔胞元最薄弱处附近的弹着点弹体偏转角度明显小于其他位置;空腔胞元空间排布的非对称化处理能够提升空腔结构对子弹的偏转效果。

To improve the ballistic performance of metal targets,a metallic structure composed of a series of crescent-shaped cavity cells,whose spatial distribution is similar to a honeycomb,was proposed.Each cavity cell is formed by two balls with an identical diameter offset by a certain distance and its shape looks like a crescent moon.The deflection performance of crescentshaped cavity structures impacted by 12.7 mm armor-piercing incendiary projectile cores at an initial velocity of 818 m/s was studied numerically.Based on 3D voxel models,numerical simulation was carried out by using the finite element code ABAQUS/Explicit.The deflection angle of the projectile related to the initial impact direction was measured in the process of penetration simulation.By comparing with the experimental results in the literature,a virtual test was carried out to verify the validity of the finite element model.The influences of crescent shape,hitting position and space arrangement of cavity cells on the deflection performance were analyzed.The results show that the crescent shape has a significant effect on the overall deflection performance of the target.The deflection angle of the projectile increases with the increase of the cavity diameter,but the protection performance of the structure with larger cavity diameter becomes weaker.A cavity diameter of 18 mm with the offset distance of 5.4 mm may be appropriate when considering a high deflection performance without significant drop of the protection performance of the target plate.The target impacted by the projectile at different hitting positions shows different deflection performances.The deflection angle of the projectile is much large at those positions where the material distribution has a high asymmetry.The asymmetric treatment of the space arrangement of cavity cells can improve the deflection effect of the cavity structure.The deflection mechanism of the cavity structure is that when the projectile penetrates the interface between the material and cavity inside the target plate,the projectile is subjected to an asymmetric force distribution,which affects the subsequent penetration process.