中等厚度金属靶板的三阶段贯穿模型

研究了刚性尖头弹侵彻贯穿中等厚度金属靶板问题。考虑靶板背表面开裂的影响，在有限厚度金属靶板两阶段侵彻模型的基础上，引入开裂侵彻深度概念，提出一个三阶段侵彻贯穿模型。基于不可压缩弹塑性材料有限球形空腔膨胀理论和等效拉伸应变断裂准则，得到弹头表面径向压力、开裂侵彻深度的解析解和弹头侵彻阻力的数值解，由Runge-Kutta法求解弹体运动微分方程，得到极限速度、剩余速度的数值解。与小截锥刚性锥头弹侵彻铝合金靶板弹道试验数据比较，本文模型计算结果与试验吻合很好。计算表明，弹头长度和靶板厚度对侵彻阻力的影响十分明显。

A Three-stage Model for the Perforation of Moderately Thick Metallic Plates

Taking account of fracture of the back surface of target,the finite spherical cavity expansion approximation and the two-stage penetration model were modified to develop a new three-stage perforation model for moderately thick metallic plates struck by a rigid projectile.A new concept called fracture penetration depth was proposed,which refers to the maximum penetration depth before the back face of the plate cracks.Closed-form equations for the fracture penetration depth and equations for the penetration resistance force on the projectile head were derived for a conical-head projectile with a small spherical tip which simulates the truncated nose of real projectiles.Penetration resistance force,residual velocity-penetration depth history,ballistic limit and final residual velocity of the projectile were obtained numerically by solution of the equation for projectile motion with Runge-Kutta method.The predicted results are in good agreement with previously published test data.The present model is applicable to those perforation problems where the length of the projectile head is larger or less than the plate thickness.