Energetic Materials Frontiers (Dec 2024)
Shock reaction model for impact energy release behavior of Al/PTFE reactive material
Abstract
Metal/polymer reactive materials are inert under normal temperature and pressure conditions and possess a certain level of structural strength, allowing them to be fabricated into components such as fragments. However, under strong impact, they can undergo intense reactions and release a large amount of chemical energy. Al/PTFE is one of the most typical metal/polymer reactive materials. When reactive materials are used to make warhead fragments, they can deliver a significant amount of chemical energy to the target in addition to the kinetic energy damage. When used as the core of a PELE (Penetrator with Enhanced Lateral Efficiency) projectile, reactive materials can enhance the fragmentation of the projectile shell after penetrating the target, causing both physical and chemical damage. The reaction mechanism of these materials is complex, and it is difficult to directly monitor the chemical reaction process. The shock energy release process of reactive materials is different from the shock detonation process of traditional high explosives. Therefore, the existing reaction models describing the shock detonation process of explosives are not applicable to describe reactive substances. Consequently, understanding and describing the shock reaction characteristics of reactive materials on a macroscopic scale is crucial for promoting their engineering applications. Based on the plate impact experiments and thermal analysis of typical Al/PTFE reactive materials (with a mass ratio of Al to PTFE of 26.5:73.5), this paper proposes a phenomenological shock reaction model. The shock reaction model can describe the chemical reaction behavior of materials during shock compression. The mathematical expressions, programming implementation principles, and methods for obtaining model parameters of the shock reaction model are elaborated. At the same time, the shock reaction model is embedded into the material library of the LS-DYNA nonlinear dynamic simulation software as a secondary development. Numerical simulations of the behavior of Al/PTFE reactive materials in several typical applications are carried out. The results show that the shock reaction model can well describe the mechanical-thermal-chemical coupling behavior of Al/PTFE reactive materials under shock compression. This is of great significance for accelerating the engineering application of reactive materials in military fields such as weapon damage.
