Hot-spot initiation of heterogeneous explosives
It is generally accepted that the shock initiation of heterogeneous explosives begins with the formation of hot spots in the vicinity of microstructural defects such as voids, grain boundaries, and phase boundaries where there can be significant localized deformation as a result of material viscosity, plastic work, and intergranular friction. This phenomenon is described in the context of a recently developed theory of chemically reacting, multiphase mixtures. In particular, we consider a granular explosive with an energetic binder (e.g. PBX-9404) and represent it as a three-phase, saturated mixture consisting of the granular reactant, the binder phase, and the product gases. Under dynamic loading, viscous dissipation results in high temperatures in the binder phase which subsequently thermally explodes to form product gases. Decomposition of the granular reactant is achieved by laminar grain burning. This model has been incorporated into a 1-D Lagrangian finite-difference code (WONDY) and the evolution of compressive shock and acceleration (ramp) waves have been calculated for PBX-9404. The calculated wave growth at the front, as well as the reaction-induced pressure wave behind the wave, are shown to be in good agreement with experimental observations.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (USA); Florida Univ., Gainesville (USA)
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 6457196
- Report Number(s):
- SAND-80-2438C; CONF-810602-30; ON: DE81027801
- Resource Relation:
- Conference: 7. symposium on detonation, Annapolis, MD, USA, 19 Jun 1981
- Country of Publication:
- United States
- Language:
- English
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