Discrete element method simulation of energy dissipation mechanisms of HMX explosive particles under drop-weight impact

A thermal-mechanical coupling model describing energy dissipation of cyclotetramethylene-tetranitramine (HMX) explosive particles subjected to drop-weight impact is developed based on the discrete element method (DEM). The energy dissipation resulting from plastic deformation, sliding friction and rolling friction due to the interaction of HMX explosive particles can be effectively captured during the impact loading process by DEM. The simulation results illustrate that the energy dissipation increases with the increase of drop-weight height, particle size, and moment of inertia of particle, but the energy dissipation decreases when the sample mass increases from 40 mg to 55 mg at the same impact loading condition. Moreover, it is found that the energy dissipation is dominated by interparticle friction dissipation in the absence of internal defects such as cracks or pores, which is in agreement with previously published results. Furthermore, this work reveals that the main contribution of friction dissipation is derived from rolling friction dissipation.