分析金属装甲弹道极限的两阶段模型

基于大量弹道试验分析,考虑靶板背面自由边界的影响,提出一个分析刚性尖头弹垂直撞击中等厚度理想弹塑性材料靶板弹道极限的两阶段工程模型.由圆柱形空腔膨胀理论和功能原理导出第一阶段延性扩孔耗能表达式,按薄靶板最小穿透能量的简化分析模型计算第二阶段耗能,由两阶段总的耗能最小确定第一阶段的侵彻深度,从而得到最小穿透能量的解析解.经与金属装甲弹道试验比较,表明两阶段工程模型计算结果与试验吻合较好,比现有单一延性扩孔模型精度高.

A TWO-STAGE MODEL FOR ANALYSIS OF BALLISTIC LIMIT OF METALLIC TARGETS

A new engineering model is developed for analysis of ballistic impact of moderately thick metallic plates struck by non-deformable projectiles with conical and ogival noses. The model considers two interconnected perforation stages. In the initial stage, it is characterized by ductile hole enlargement and radial plastic flow of the plate materials. The second stage is characterized by bulging and petalling occuring on the rear face of plates. Formulas for energy dissipated in the plate during ductile hole enlargement are derived from cylindrical cavity expansion theory. Wierzbicki formula for petalling of thin plates is used to evaluate the energy dissipated by bulging and petalling in the second stage. The penetration depth X1 at the end of the first stage is determined by minimizing the total energy dissipated in the plate during the two stages. Analytical formulas for critical impact energy and ballistic limits are obtained. Comparison is made with previously published ballistic test data and the results of cylindrical cavity expansion approximation and single-stage ductile hole enlargement models.