双层预制破片爆轰驱动早期行为研究

Research on the Behavior of Initial Stage about Explosively-driven Double-layered Premade Fragments

通过分析方/球形双层预制破片在典型排布方式下的受力状态,并结合炸药爆轰驱动能量的释放规律,将双层破片的加速过程分为两个阶段,即冲击碰撞加速阶段和气体产物膨胀加速阶段;采用闪光X射线照相方法测量破片在冲击碰撞加速阶段的加速过程,然后结合经典Gurney公式计算出气体产物膨胀加速效果;对典型钨、钢材料的方/球形双层破片进行了试验和理论分析。结果表明,外层破片的初速均高于内层破片,其中,外、内层方形钢破片的初速比值最大,约为1.48,且外层方形破片由于受到较强拉伸波作用而出现明显破损;而外、内层球形钨破片的初速比值最小,仅为1.08,且球形破片大多为斜侧方对称受力,难以形成较强且较为集中的拉伸波,使得外层破片的完整性较好。

By analyzing the stress state of double-layered cubical/spherical prefabricated fragments under the typical arrangement and combining the release law of detonation driving energy,the acceleration process of double-layered fragments was divided into two stages,namely,shock acceleration stage and expansion acceleration stage of gas product.The acceleration process of fragment in the shock acceleration stage was measured by flash X-ray photography,the acceleration effect of gas product expansion was calculated by classical Gurney formula.The experimental and theoretical analysis of the double-layered cubical/spherical fragments of typical tungsten and steel materials were carried out.The results show that the initial velocity of the outer layer fragments is higher than that of the inner layer fragments,wherein,the ratio of the initial velocity of the inner and outer layered cubical steel fragments is the largest,which is about 1.48,and the outer layered cubical steel fragments is obviously damaged due to the strong tensile wave action.The ratio of the initial velocity of the inner and outer layered spherical tungsten fragments is the smallest,which is only 1.08.Moreover,the spherical fragments are mainly subjected to the symmetrical force from the inclined sides,so that it is difficult to form a stronger and more concentrated tensile wave,resulting in better integrity of the outer fragments.