Shock compaction of porous compounds with application to PBX-9501 and HMX

Abstract

This report pursues assessment and analysis of earlier experimental shock wave studies of HMX based PBX-9501 explosive material, a mixture of HMX molecular crystal and polymer binder. The effort also undertakes exploring underlying physics of the dynamic compaction and deformation of granular mixtures, and in pursuing compaction model improvements relevant to the shock wave equation-of-state. The model development is applied to experimental unreacting shock strength and Hugoniot data on modestly porous PBX-9501 material tested at Los Alamos National Laboratory (LANL) in the 1980's and again in the 1990's. Time-resolved shock wave experiments lend insights into the energy dissipation dynamics. Complementary detailed material microstructure studies constrain dissipation mechanisms on the microscale. Pore compaction is modelled and the potential for heterogeneous hot-spot formation is assessed. Results of the effort uncover details of the unreacting shock compaction response of this mixture material. Specifics of shock wave structure and the dependence of structure on shock amplitude are explored that lend insights into microstructure dissipation mechanisms responsible for onset of reaction. The report closes with a perspective on dissipation dynamics within the unreacting structured shock wave response of PBX 9501 explosive.