展开式EFP战斗部复合破片场成型的数值模拟

Numerical Simulation on Composite Fragment Field Formation of Expansion EFP Warhead

为实现战斗部毁伤威力的可控化,提出了一种外围采用刻槽壳体且可展开不同角度的EFP战斗部。基于ICEMCFD软件对展开式战斗部进行了O型网格划分,采用Autodyn软件对EFP和预控破片群相结合的复合破片场成型过程进行了数值模拟,获得了中心与外围装药量、外围装药起爆方式、展开角度对复合破片场成型特性的影响规律,利用X光试验验证了数值模拟方法的有效性。结果表明,随着中心装药半径的增大,EFP的速度和长径比逐渐增大,断裂现象愈加明显,而预控破片的飞散速度逐渐减小;外围装药顶部四点起爆方式形成的破片速度高于顶部二十点和内侧二十点起爆方式下的破片速度;闭合与展开时预控破片的最大速度分别出现在距起爆端约60%和33%处,且随着展开角度的增加,远离起爆端的预控破片速度逐渐减小,与闭合状态相比,展开75°状态下EFP侵彻深度减少了36%,而孔径增大了38%。选取中心装药半径20mm、展开角度为45°~60°时,复合破片场的汇聚较明显且成型控制效果较佳。

To realize the controllability of warhead damage power, an EFP warhead with a peripheral grooved casing was proposed, which can expand different angles. Based on ICEM CFD software, the O-type meshing of the expansion warhead was carried out. Autodyn software was used to numerically simulate the forming process of composite fragment field combining EFP with pre-controlled fragment group. The influence law of the center and peripheral charge mass, peripheral charge initiation mode and expansion angle on the forming characteristics of the composite fragments field was obtained, and the effectiveness of the numerical simulation method was verified by X-ray test. The results show that with the increase of the center charge radius, the velocity and length-to-diameter ratio of EFP increase gradually, the fracture phenomenon becomes more and more obvious, while the scattering velocity of the pre-controlled fragment decreases gradually. The fragment velocity formed by the four points initiation mode at the top of peripheral charge is higher than the fragment velocity under twenty points initiation mode at the top and the twenty points initiation modes at inside. The maximum velocity of pre-controlled fragments at closure and expansion state occurs at about 60% and 33% from the detonation side, respectively, and with the increase of expansion angle, the pre-control fragment velocity away from the detonation side is gradually reduced. Compared with the closure state, the EFP penetration depth is reduced by 36% and the aperture is increased by 38% when the expansion angle is 75°. When the center charge radius is selected as 20mm and the expansion angle is 45°-60°, the convergence of the composite fragments field is more obvious, and the molding control effect is better.