Multi-Scale Modeling for Combined Shock-Shear Initiation of Energetic Solids

摘要

Multi-scale interactions between initially planar deformation waves in heterogeneous energetic solids and macro-scale boundaries were computationally examined to characterize wave interaction structures and dissipative heating responsible for combustion initiation. The macro-scale response was described by a continuum theory that accounts for elastic and inelastic volumetric deformation in a thermodynamically consistent manner. The meso-scale response was described by conservation principles and an elastic- viscoplastic constitutive theory to predict contact induced nonlinear deformation and thermomechanical fields within particles. Predicted meso-scale fields were locally averaged and compared to independent predictions given by the macro-scale model. Wave-boundary interactions resulted in dispersed wave structures that are analogous to Mach stems in gas dynamics, with maximum dissipative heating rates occurring along bounding surfaces away from the stagnation region, which substantially increased the fraction of mass locally heated to elevated temperature.