Determination of state equation parameters for Al/EP/B energetic materials under high-speed impact

When insensitive energetic materials are subjected to high-velocity impact loads, intense chemical reactions occur accompanied by significant energy release. This dynamic response process includes unreacted stage, reaction transition stage, and complete reaction stage. Focusing on the Al/Ep/B reactive material system, this study obtains Grüneisen state equation parameters during the unreacted stage through symmetric collision experiments; determines the JWL state equation during the reaction stage by impact initiation experiments and the parameters for transition zone of the ignition growth model considering the effect of shock-induced temperature rise through statistical induction. A full-stage simulation of the entire process, from projectile impact compression to material reaction triggering then deflagration energy release, is carried out on the Autodyn finite element platform incorporating multi-stage state equation subroutines. The accuracy of the experimentally obtained parameters is validated by comparing the simulation results with temperature field inversion data from high-speed camera. The results show that the Hugoniot obtained from the numerical simulation coincides with experiment results, and the impact initiation temperature field inversion data match up well with the numerical simulation, with a peak temperature of approximately 1800 K. The numerical simulation reveals that the reaction degree of Al/Ep/B reactive materials is relatively low at a collision velocity of 610.52 m·s −1 , but increases significantly with higher impact velocities. • Hugoniot parameters were obtained through symmetric impact tests. • Detonation velocity of the reactive material was measured precisely using the probe method. • Radiation thermography was used for temperature field inversion. • The impact ignition process of reactive materials was simulated via finite element subroutines.