Dynamic hot spot induced damage in energetic materials using a hot-spot surrogate model

The interaction of a shock wave with microstructural defects leads to energy localization and a sudden increase in local temperature. Due to the small time and length scale of the interaction of the shock with defects, it is computationally expensive to capture simultaneously the mechanics that leads to the high temperature spike and the macroscopic damage. Therefore, we developed a surrogate model to predict the heat rate for a given shock strength to replace the explicit calculation of the defect deformation and the resulting temperature spike. This model is integrated in finite element simulations to predict the effect of the local heat rate on the fracture patterns that develop under shock loading conditions with pressure pulses between 0.33 and 0.98GPa on a octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) particle embedded in a Sylgard matrix.