卵形弹体超高速侵彻砂浆靶的响应特性

为研究砂浆靶目标在动能弹超高速撞击下的破坏响应，利用2级轻气炮开展卵形头部钢杆弹以1 200Symbol~A@2 400 m/s速度侵彻砂浆靶的实验。根据侵彻实验结果，分析得到：靶体开坑直径和开坑深度与撞击速度呈线性关系；随着撞击速度的增加，侵彻深度呈现先线性增加、后逆减、再缓慢增加的趋势，分别对应刚性侵彻、半破碎侵彻和破碎侵彻3种截然不同的侵彻机制。基于前述分析，以内摩擦理论为基础，结合弹体质量损失函数，推导得到刚性侵彻和半破碎侵彻深度计算公式，并与实验结果进行对比。结果表明：考虑弹体质量损失的侵彻深度计算模型理论计算结果与实验结果吻合较好，解释了超高速侵彻过程中侵彻深度逆减的特殊现象，揭示了砂浆靶中侵彻深度变化规律的内在机理。

Response Characteristics of Hypervelocity Ogive-nose Projectile Penetrating into Mortar Target

To study the damage effects of mortar targets subjected to hypervelocity impact of kinetic-energy projectiles, the ogive-nose steel rods launched from a two-stage light gas gun were experimentally penetrated into mortar targets at 1 200-2 400 m/s. The linear dependences of cratering diameter and depth on the initial impact velocity are found from the experimental results. The penetration depth increases linearly first and then decreases sharply, and again increases slowly with the increase in impact velocity. Three penetration mechanisims, i.e., rigid penetration, semi-fracture penetration and fracture penetration, were observed,respectively, with the increase in impact velocity. A calculation model based on the internal friction penetration theory, in which the mass loss function of projectile is considered, is developed for predicting the penetration depths of rigid penetration and semi-fracture penetration. The calculated results were compared with the experimental results. The results indicate that the calculated results of the proposed model are in well agreement with the experimental results in terms of non-dimensional penetration depth. The special phenomenon of penetration depth reduction in the process of hypervelocity penetration is explained, and the inherent mechanism of variation law of penetration depth is further revealed.