Evaluating microstructure features for shock sensitivity at the mesoscale

Developing insight into the microstructure dependence on observed shock initiation sensitivity of energetic materials under a variety of mechanical stimuli and thermodynamic conditions will result in much needed capabilities towards predicting detonation performance. Current state-of-the-art experiments lack the connection between microstructure features and sensitivity, thus we turn to simulations for further investigation. To date, these high-fidelity computational efforts have often been limited to studying the criticality of single pore collapse; while interesting, it has not yet been feasible to predict the sensitivity of a more realistic multipore microstructure. Our work involves well-defined sets of simulations with increasing degrees of complexity to study materials behavior across a variety of shock conditions and length- and time-scales. These efforts define a suite of reaction progress metrics that better resolve the buildup of a deflagration wave, and we will discuss important computational details that impact their interpretation. Establishing connections between geometric relationship of pores, we can predict criticality thresholds built up from small scale tests. We conclude with compact, data-driven models to predict the response of the global metrics.