Surrogate hot-spot models for high-fidelity simulations of detonation in energetic materials

Localized regions of high temperature, known as hot-spots, develop when materials are subjected to shock loading. This process is controlled by the microstructure of the material, including voids, micro-cracks, grain boundaries, and interfaces. As a result, local burning in an energetic material may lead to the formation of a reactive shock front.



The length scales associated with the processes at the microstructure level range from nanometers to micrometers. However, typical run to detonation distances are observed at the millimeter scale. We developed surrogate hot-spot models that are used in shock simulations to understand the effect of microstructure on detonation. These surrogate models predict the local temperature and pressure and are informed from atomistic and mesoscale simulations that include, plastic deformation, friction, jetting, and recompression. Interestingly, some of these models present scaling behavior from nanometers to micrometers. We present finite element simulations of shock compression with parametric studies of defect density and distribution to observe their relationship to the detonation wave velocity, and run to detonation distance. Furthermore, the influence of the shock wave on the initiation reaction site and the shape of the shock front are explored.