采用刚塑性不可压缩的介质模型,用极限分析理论的上限方法,通过建立动力学许可速度场分别得到介质对平头和锥形撞击体的阻力分量,采用数值分析的方法对阻力公式进行简化。根据阻抗曲线的特征,表征了复杂震塌与贯穿厚度的临界条件和计算原理,分别得到了平头和锥形撞击体作用下具有物理基础的震塌与贯穿临界厚度近似计算公式,根据计算分析得到用撞击体端部形状系数表示的统一的公式形式。通过与经验公式的对比分析,验证了该方法的可靠性和实用性。
A rigid-perfectly plastic model in incompressible medium is used in this paper. By setting a dynamical admissible velocity field, the resistance of medium to a flat-nosed block and a conical-nosed block are analyzed with an upper-bound way of limit analysis theory respectively, and the resistance formulae are simplified by numerical analysis. According to the characteristics of resistance curves, the critical thickness conditions and calculating theory of spalling and penetration are represented and the approximate calculation formulae under the impact of a fiat-nosed block and a conical-nosed block with physical bases are obtained respectively, and a unified formula with the shape factor of blocks is integrated. The reliability and practicality of the method is verified by the comparison with experimental formulae.