Numerical Simulation of the Behind-Target Overpressure Effect from Reactive Fragments Penetrating Thin Plates

Due to their pronounced post-penetration damage effects, the reaction behavior and overpressure effects of reactive fragments following penetration have garnered significant attention. This study conducts a numerical simulation of the overpressure effects resulting from the penetration of thin plate targets by reactive fragments. By integrating smoothed particle hydrodynamics, finite element method, finite volume method, and an energy release model for reactive fragments, a numerical simulation approach for analyzing the overpressure effects post-penetration is proposed. The overpressure distribution characteristics and the variation of peak overpressure with penetration velocity are determined for ϕ10 × 10 mm Al/W/PTFE reactive fragments penetrating a 3 mm target plate at velocities ranging from 700 m/s to 1 100 m/s. The results indicate that the evolution of overpressure distribution inside the sealed air tank is correlated with the dispersion of energetic fragments. As the penetration velocity increases, high-pressure regions change from sparse to dense, with a significant pressure rise, reaching a transient peak of 1 753. 9 kPa at 1 000 m/s. With further velocity increase, the overpressure begins to decline but at a slower rate. This study reveals the overpressure effects of energy release at different velocities, providing valuable references and numerical methods for warhead design and damage assessment.