Coarse-Grained Reactive Model of RDX: Conjoining the Continuum and Atomistic Resolution

Accurate models for predicting the thermal, chemical, and mechanical properties of high explosive (HE) materials are of great interest for both military and civilian usage of these materials in a safe and efficient manner. Computational models with atomistic resolutions have demonstrated accurate portrayal of HE, but their computational cost constrain their application to systems with O(100 nm, ns). To overcome such limitation, reduced-order chemistry Arrhenius-like models that can predict the sensitivity of μm-scale hotspots have been developed. However, such models are incapable of capturing phenomena where the material behavior at the molecular level significantly affects the system. Here, we bridge the gap between atomistic and continuum models by developing a particle-based, coarse-grained model of an HE material that utilizes generalized dissipative particle dynamics with reactions (GenDPD-RX). By incorporating the chemical kinetics from the Arrhenius-like models while parametrizing the GenDPD-RX model based on atomistic simulations, our model accurately captures the material response to shocks with multiple orders of improvement in computational efficiency. We expect that such models will enable future investigation of HE at length and time scales previously inaccessible. Approved for public release; distribution is unlimited.