This paper presents an analytical study on the cavitation phenomenon during penetration of a rigid projectile into an elastic-plastic target. The developed analytical approach is based on the general solution of the quasi-static and non-stationary dynamic cylindrical/spherical cavity expansion problem with assigned kinematic boundary condition at the cavity boundary (variable, time dependent radial velocity). An analytical projectile-target separation criterion is developed for a projectile having an arbitrary shape and for a target described by a simplified material model with a locked equation of state and a linear shear failure relationship. This relatively simple model may represent the behavior of different materials reasonably well yet allow an analytical solution of the problem. The paper derives the analytical expression of the contact zone size using both the cylindrical and spherical cavity expansion approaches and presents the related normal contact stresses acting on the projectile nose surface that maintains contact with the target. Examples of the developed formulation is presented for ogive nose and Rankine ovoid projectiles hitting aluminum targets, with a constant shear failure envelope, at different velocities and comparisons with known analytical and numerical solutions are shown. The effect of projectile and medium properties on the size of the contact zone are studied.

本文对刚性弹丸穿透弹塑性靶时的空化现象进行了分析研究。所开发的分析方法是基于准静态和非平稳动态圆柱/球腔扩张问题的一般解决方案，并在腔边界处分配了运动学边界条件（变量，随时间变化的径向速度）。针对具有任意形状的弹丸以及由具有锁定状态方程和线性剪切破坏关系的简化材料模型描述的弹丸，开发了一种弹丸-靶标分析分离标准。这个相对简单的模型可以很好地表示不同材料的行为，但可以对问题进行分析解决。本文使用圆柱和球形腔扩展方法得出了接触区大小的解析表达式，并提出了作用在与目标保持接触的弹头表面上的相关法向接触应力。给出了发展中的例子，这些例子适用于以恒定速度剪切破坏包络线以不同的速度撞击铝靶的钝鼻和兰金卵球形射弹，并显示了与已知分析和数值解的比较。研究了弹丸和介质性质对接触区大小的影响。给出了发展中的例子，这些例子适用于以恒定速度剪切破坏包络线以不同的速度撞击铝靶的钝鼻和兰金卵球形射弹，并显示了与已知分析和数值解的比较。研究了弹丸和介质性质对接触区大小的影响。给出了发展中的例子，这些例子适用于以恒定速度剪切破坏包络线以不同的速度撞击铝靶的钝鼻和兰金卵球形射弹，并显示了与已知分析和数值解的比较。研究了弹丸和介质性质对接触区大小的影响。