超高速弹对花岗岩侵彻深度逆减现象的理论与实验研究

Theoretical and experimental studies on the phenomenon of reduction in penetration depth of hyper-velocity projectiles into granite

利用100/30 mm二级轻气炮开展1.2~2.4 km/s着速下卵形长杆高强钢弹对花岗岩的侵彻效应实验研究,获得弹/靶宏观破坏形态,测量侵彻深度和侵彻后弹体回收质量等参数。实验结果表明:随着侵彻速度增加,侵彻深度呈现先线性增大后急剧降低再缓慢增长的三段式变化趋势,分别对应于3种不同的侵彻机制——刚性侵彻,半流体侵彻和流体侵彻。结合半流体侵彻阶段弹体半径微增而弹体质量骤减的实验现象,提出考虑弹体质量损失的侵深计算模型,并与实验结果相印证;分析弹体质量损失对弹体侵彻过程的影响,揭示超高速弹对花岗岩侵彻深度逆减现象的内在机制。

The penetrations of long-rod steel projectiles of high-strength at 1.2 - 2.4 km/s into granite targets using the two-stage light-gas gun of 100/30 mm are carried out to investigate the effect and mechanisms of penetration. The macro-damage of the targets and projectiles, the penetration depth and the mass of the recovered projectiles are obtained. The penetration depth increases firstly, then decreases sharply and finally increases gently as the increasing of striking velocity, which correspond to the rigid body penetration, semi-hydrodynamic penetration, and hydrodynamic penetration respectively. In the stage of semi-hydrodynamic penetration, the mass of the recovered projectiles decreases rapidly, while the projectile diameter changes slightly. A model for calculating the penetration depth taking account of the loss of projectile mass is presented. The calculated results fit the experiment data well. The influence of the loss of projectile mass on penetration is analyzed, and the internal mechanism of the reduction phenomena of penetration depth is revealed.