A cross-scale hotspot ignition optimisation model based on void collapse and its interaction

A cross-scale hotspot ignition optimisation model is proposed to characterise the ignition stage in pressed energetic materials (PBXs). In the model, to account for heterogeneous effects, a multi-complex nested ubiquitiform optimisation model is developed to characterise the meso-structure feature of PBX and then used to predict the hotspot distribution of PBX. The intensity of hotspot is obtained based on meso-scale void collapse simulations, and the influence of the interaction between voids on hotspot intensity is considered. Then, a cross-scale hotspot ignition optimisation model is developed based on the hotspot distribution and the Arrhenius model. Based on the physical and chemical properties of the material and without the calibration of experimental parameters, the model can calculate the reaction rate of the hotspot ignition for PBX 9501. Finally, the upper and lower limits of ignition reaction rate are obtained by substituting maximum hotspot energy and minimum hotspot energy into the hotspot ignition optimisation model, which provides a certain basis for the safety evaluation and design of explosives.