A Morphologically Aware Model for High Explosives

Predicting the performance and safety of explosive devices relies upon an understanding of the underlying hot spot mechanisms. Explosive compositions which only differ in microstructure are known to have significant variations in initiability. Conventional reactive flow models do not directly incorporate microstructure information, therefore different parameter sets must be developed to account for lot-to-lot variations. We develop a morphologically aware detonation model for high explosives that incorporates pore size distribution data. Pore size data is used to define the number of hot spots that are ignited as a function of the effective plastic strain. The ignition sites then burn spherically. Initial burn products react through a pseudo-diffusion-controlled reaction to form the final products. Our model is simulated using ALE3D and the parameters controlling the initiation and burning are optimized using Pop-Plot and embedded pressure gauge data from nominal experiments. The calibrated model is then used to predict the effect of altering the initial porosity distribution on the run-to-detonation.