Shear band formation in plastic bonded explosive (PBX)
Adiabatic shear bands can be a source of ignition and lead to detonation. At low to moderate deformation rates, 10-1000/s , two other mechanisms can also give rise to shear bands. These mechanisms are: 1) softening caused by microcracking and 2) a constitutive response with a non-associated flow rule as is observed in granular material such as soil. Brittle behavior at small strains and the granular nature of HMX suggest that PBX-9501 constitutive behavior may be similar to sand. A constitutive model for the first of these mechanisms is studied in a series of calculations. This viscoelastic constitutive model for PBX-9501 softens via a statistical crack model. A sand model is used to provide a non-associated flow rule and detailed results will be reported elsewhere. Both models generate shear band formation at 1-2% strain at nominal strain rates at and below 1000/s. Shear band formation is suppressed at higher strain rates. Both mechanisms may accelerate the formation of adiabatic shear bands.
- Research Organization:
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 628804
- Report Number(s):
- LA-UR-97-2857; CONF-970707-; ON: DE98000627; TRN: AD-a337 548
- Resource Relation:
- Conference: Meeting of the topical group on shock compression of condensed matter of the American Physical Society, Amherst, MA (United States), 27 Jul - 1 Aug 1997; Other Information: PBD: Jul 1997
- Country of Publication:
- United States
- Language:
- English
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