Jet forming of Al/PTFE-W/Cu double-layer liner considering reactivity and damage to medium-thick concrete target

Abstract

Because the metal jet with high specific kinetic energy and high-density cannot release energy and damage inside the target, the later fluoropolymer-based reactive material jet can release energy and deflagration in the penetrating hole, but its mechanical properties are not as good as that of the high-density insensitive metal liner, hence it does not have strong penetration ability. Therefore, in order to seek the liner structure with the respective advantages of metal and reactive material, it has become a new direction to improve the damage ability of warhead. In this paper, the jet forming of Al/PTFE-W/Cu double-layer liner and the damage characteristics of concrete medium-thick target are studied by numerical simulation, combined with ignition growth model and Arrhenius reaction model. The results show that Al/PTFE reactive material adheres to the slug of W/Cu jet and advances together, which effectively combines the characteristics of strong penetration of metal jet and after effect deflagration of reactive material. The penetration of metal jets and the deflagration of reactive materials lead to concrete center cracking and crack propagation. Part of the reactive material and 6 cm concrete particles on the surface of the target will be thrown out of the target with the airflow of the reaction product, and concrete particles with diameters of 9–12 cm will be compacted to both sides of the hole. The reaction of the reactive material increases under the detonation of the explosive, and it collides with the surrounding concrete when entering the intrusion hole. The secondary reaction promotes the increase of the reaction degree, which leads to the cracking and crack propagation of the concrete target center. Some reactive materials are used for opening and releasing energy near the opening. Only a small amount of active materials reach the bottom of the hole, which is difficult to effectively damage the deep structure of the concrete. Therefore, effectively adjusting the reaction threshold of the reactive material plays a vital role in the damage performance of the Al/PTFE-W/Cu jet, which will also lay a foundation for the damage characteristics of the strong penetration-energy release initiation of the energetic double-layer liner.