Effects of crystallography on hot-spot formation in porous RDX single crystals

Abstract

The thermomechanical behavior of porous RDX single crystals is studied under dynamic loading using an anisotropic dislocation-based crystal plasticity model that accounts for deformation-induced heating. A micromechanics-based framework is proposed to account for micro-inertially confined dynamic collapse of pores. A suite of finite element calculations are carried out to systematically elucidate the role of crystallographic orientation on hot-spot formation. Under particular loading orientations, the porous RDX crystals are found to be quite sensitive to deviatoric and volumetric strain localizations, even for loading situations that do not particularly promote strain localization in isotropic materials. Due to the anisotropy-induced strain localizations, fairly severe hot-spots are predicted even under moderate applied strains. The susceptibility of porous RDX to strain localize and form severe hot-spots under particular loading orientations has important implications for accidental detonation of these energetic materials.