Mesoscale modelling of the shock detonation transition of a heterogenous explosive.

Mesoscale simulations of the Shock to Detonation Transition (SDT) of heterogeneous explosives provide a means to better understand the SDT at the macroscale. In literature, there has been efforts to determine how hot spots form in an explosive microstructure after the impact of a flyer plate. However, studies that focused on hot spot growth and its influence on the shock acceleration are scarcer. In recent experimental studies by Johnson et al. [1, 2], hot spots in HMX monocrystals and polycrystals were observed. These studies suggested that hot spots developed mainly on the surface of the crystals and that the grains were consumed by the propagation of a deflagration front. In this present work, mesoscale simulations of an explosive composed of HMX were performed. Chemical reactions in the explosive were modelled through the propagation of a deflagration front at the surface of the crystals, based on [1, 2]. Accordingly, the simulations did not focus on the effects of the explosive microstructure on the hot spot formation, but essentially on their growth and its influence on the SDT. The wedge test configuration was employed on a microstructure generated by a 2D-Voronoï scheme. The shock/detonation position was post-processed from the simulations and used to determine the run-to-detonation distance (RDD) for different impact velocities. The Pop-plot obtained from these RDD was then compared to experimental Pop-plot data. [ABSTRACT FROM AUTHOR]