Dynamic energy-release model for reactive composite jets impacting spaced plate-enhanced sealed chamber

Reactive composite jets combine the penetration capability of metallic jets with the secondary energy release of reactive materials, but a unified model that links jet formation, penetration, reaction evolution, and aftereffect overpressure remain incomplete. This study proposes a dynamic energy-release theory for reactive composite jets impacting multi-spaced plates at large stand-off distances. The framework couples smoothed particle hydrodynamics-Lagrange model with Arrhenius thermochemical kinetics and a shrinking-core reaction model to quantify the time-dependent reaction degree of reactive particles during jet formation and penetration. It further identifies the effective reacting mass entering the post-target chamber and incorporates reaction-time and mass-loss effects into aftereffect overpressure prediction. Static explosion experiments and numerical simulations were conducted for reactive-material-copper and reactive-material-titanium composite jets, with an inert copper jet used as the reference. The results indicate that reactive composite jets produce larger reaming damage and higher aftereffect overpressure than the inert jet. The proposed model also shows closer agreement with experimental overpressure data than thermochemical equivalence and delayed-reaction models. These results provide a physically interpretable tool for evaluating coupled penetration and post-target energy release in reactive shaped-charge systems.