Dynamic evolution of damage and temperature of PBX subjected to low-velocity impact

The mechanical–thermal–chemical coupled peridynamic (PD) model is employed to investigate the mechanical damage accompanied by the temperature rise of polymer bonded explosives (PBXs) subjected to low-velocity impact. The evolution of damage and temperature corresponding to three different impact stages of approach, rebound, and separation is analyzed in detail. The simulation results indicate that the damage of PBX toward the impact plate is characterized by pulverized damage and the damage backward the impact plate is characterized by discrete cracks for a relatively higher impact velocity. The number of PD material points with their temperature greater than a prescribed critical value increases with the progress of simulation time and, finally, reaches a saturated value, which is exponentially dependent on the impact velocity. Both the number and size of hotspots as a function of simulation time are analyzed via the cluster analysis method. The results reveal that both of them exhibit complicated behaviors associated with the coalescence or separation processes of PD material points with relatively higher temperature. The current study reveal the coupled relationship between mechanical damage, temperature rise, and loading processes and can help to deepen the understanding of complicated behaviors of non-shock ignition of PBX under low-velocity impact loading.