A 3D-DEM study on influencing factors of ignition, combustion, and detonation of single HMX particles with voids

In this study, a 3D-DEM was employed to model an HMX explosive containing a large void oriented at 45°. The effects of hammer height, particle size, and void size on HMX detonation were systematically investigated. The detonation was observed at hammer drop heights of 0.1 m and 0.3 m, indicating that moderate impact energy enhances stress concentration, thereby promoting hot spot formation. Particles with a size of 150 μm were found to be the only ones capable of triggering detonation, indicating that larger particles improve stress concentration and energy transfer. Detonation could be achieved with void sizes of 64 and 100 discrete elements, as larger voids increase stress concentration and lower the detonation threshold. The reaction time of the detonation aligns with experimental results. However, the detonation pressure was found to be lower than experimental values, which is attributed to the void defect in the HMX explosive model. Overall, these findings demonstrate that an optimal void size and moderate striker height can maximize stress concentration and energy focusing, resulting in a rapid local temperature rise and the propagation of detonation waves.