Shear band formation in plastic bonded explosive (PBX)

Conference · Tue Jul 01 04:00:00 EDT 1997

OSTI ID:628804

Dey, T N; Johnson, J N

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., 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
• Country of Publication: United States
• Language: English

Related Subjects

45 MILITARY TECHNOLOGY, WEAPONRY, AND NATIONAL DEFENSE
ADIABATIC PROCESSES
CHEMICAL EXPLOSIVES
CRACKS
MATHEMATICAL MODELS
SAND
SHEAR PROPERTIES
STRAIN RATE