Understanding the Role of Microstructure in Energetic Materials Using a Predictive Hierarchical Multiscale Simulation Approach*

Composite energetic materials contain microstructural heterogeneities (i.e., crystal defects, voids, interfaces, etc.), where the community consensus is that this microstructure plays a critical role in the energetic material response. However, an understanding and characterization of its precise role for system design is lacking. This is due in part to the significant experimental challenges caused by the extreme conditions occurring at short time and length scales. Modeling and simulation are not hampered by these conditions; rather, limitations are due to the approximations made in the models and the available computational resources.

In this talk, new capabilities for investigating the role of microstructure in energetic material response through both explicit, large-scale and multiscale simulation approaches will be discussed. A hierarchical multiscale simulation approach that directly couples a coarse-grain particle level description of the chemistry and material heterogeneities (via dissipative particle dynamics simulation) to macroscale, finite element continuum simulations of an energetic material is established. The new methodology closes a gap in modeling capabilities for a key time and spatial regime in the multiscale material landscape (i.e., the mesoscale). The computational capabilities are demonstrated through at-scale comparisons of thermal cookoff and plate impact simulations with experiment to provide key insight into the role of microstructure on the response of the energetic material cyclotrimethylene trinitramine (RDX) to thermal and shock loading.