Deformation induced ignition of heterogeneous solid explosives is believed to originate at hot-spots within the material which are local regions of elevated temperature resulting from dissipative mechanisms such as plastic deformation and inter-particle friction. Inert meso-scale modeling of these materials can principally account for hot-spot formation enabling the characterization of hot-spot size and temperature distributions which are important for ignition but are difficult to experimentally resolve. By combining inert heating predictions for uniaxial waves with thermal explosion data and analysis, ignition time distributions and local fractions of ignited mass can be estimated as a function of wave strength for a given initial meso-structure (i.e., particle size and shape distribution, porosity, etc.). This information may then be used with a stochastic theory to establish the early time (or local) ignition kinetics of the material as a function of wave strength. The stochastic theory is an extension of the theory first developed by Terao5 to estimate the ignition probability of reactive gas mixtures based on measured thermal explosion time data. This study represents a preliminary step in establishing a general framework for characterizing early time shock ignition of energetic solids and its dependence on meso-structure based on inert meso-scale computations.
展开▼
