Dynamic fracture and frictional temperature rise in HMX-Sylgard microstructures under impact and vibration

Polymer bonded explosives are sensitive to impact and vibrations and can form critical hot-spots under certain conditions leading to ignition. Thus, understanding the behavior of PBXs under mechanical loading is crucial to avoid accidents during manufacturing, handling, and transport of these materials. In this study, the response of HMX-Sylgard samples is numerically studied using a finite element approach that includes dynamic damage coupled with temperature evolution due to frictional heat. At impact velocities close to 100 m/s several cracks develop and grow. Consequently, critical hot spots are observed in agreement with PBX. The maximum frictional temperature rise is found at particle polymer interfaces. The effect of crystal orientation of the particles including plasticity and orientation and cleavage planes is analyzed under vibration and impact in 3D simulations.