刚性弹侵彻有限直径金属厚靶的机理与模型研究

采用统一强度理论，考虑靶板中间主应力效应和靶体侧面自由边界的影响，得到线性硬化靶材在弹塑性阶段和塑性阶段的空腔壁径向应力的表达式，建立线性硬化靶材的统一侵彻模型，求出中低速(v₀≤1000 m/s)刚性弹体侵彻有限直径金属厚靶时侵彻阻力、侵彻深度计算公式，并利用Simpson算法对其进行求解，分析了包括强度准则差异在内的弹道终点效应的一系列影响因素。结果表明:该文计算方法可以更好地描述侵彻过程中弹靶的动态响应，还可以得到一系列基于不同强度准则的侵彻阻力和深度的解析解、对靶材在不同撞击速度下侵彻深度的区间范围进行有效预测；强度参数、弹体撞击速度、靶体半径和弹头形状对有限直径金属厚靶的抗侵彻性能均有较大的影响，其中强度参数值由1减小为0时，侵彻深度增加了22.45%；随着靶弹半径比的减小，侵彻深度不断增大，当靶弹半径比小于等于16时，侵彻深度增大的程度显著，此时靶体边界尺寸对侵彻性能的影响很大，不能继续按照半无限靶体进行计算。

RESEARCH ON MECHANISM AND MODEL OF PENETRATION INTO METALLIC THICK TARGET FINITE IN RADIAL EXTENT BY RIGID PROJECTILE

Based on the unified strength theory, considering the effect of intermediate principal stress and lateral free boundary of target to analyze the elastic-plastic stage and plastic stage of the linear strain-hardening target material, analytical solutions of radial pressure on the cavity wall are obtained and the unified penetration model of the linear strain-hardening target material is built. On this basis, resistance formulas and penetration depth formulas of the rigid projectiles with medium-low speed (v₀≤1000 m/s) penetrating into metallic thick target finite in radial extent are deduced, then their solutions are obtained by utilizing the Simpson method. Meanwhile, influencing factors for ballistic terminal effects including strength criterion difference are analyzed. The results indicate that the proposed computing method can precisely describe the dynamic responses of projectiles and targets during the whole penetration process. Through this method, a series of different criteria-based analytical solutions are obtained and the ranges of penetration depth of targets under different striking velocities are predicted effectively. Moreover, various parameters have influences on the anti-penetration performance of the target, such as the strength parameter, the striking velocity, the target radius and the shape of the projectile nose; among them the penetration depth has increased by 22.45% as the strength parameter value changes from 1 to 0. In addition, as the ratio of target radius to projectile becomes smaller, the penetration depth becomes bigger, and it has increased significantly when this ratio is less than or equal to 16. It is indicated that the penetration depth is obviously affected by the target boundary size at this time, and it cannot be calculated as an unlimited-size target any more.