MESO-SCALE SIMULATIONS OF COMPACTION WAVES IN A GRANULAR BED

Conference · Tue May 01 04:00:00 EDT 2001

OSTI ID:780526

MENIKOFF, R

A granular bed provides an extreme example of a heterogeneous material. Behind a moderate strength wave, the shock compression in a granular material is due to squeezing out pore space rather than an increase in the density of individual grains. This type of shock is known as a compaction wave. The key properties of compaction waves are displayed in mesomechanics simulations--continuum mechanics calculations in which individual grains are resolved. Fluctuations in hydrodynamic quantities occur behind the wave front due to stress concentrations at the contact between grains exceeding the yield strength and leading to localized plastic flow. Nevertheless, average wave profiles have the appearance of a dispersed shock wave, and for the most part the fluid mechanics equations, with the addition of a porosity variable, can be used as a homogenized model to describe the behavior of a granular bed. However, some aspects of the wave structure are not accounted for by the homogenized model. These include dispersion of weak waves and an elastic precursor for intermediate strength waves.

• Research Organization: Los Alamos National Lab., NM (US)
• Sponsoring Organization: US Department of Energy (US)
• DOE Contract Number: W-7405-ENG-36
• OSTI ID: 780526
• Report Number(s): LA-UR-01-2211
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
COMPRESSION
FLUCTUATIONS
FLUID MECHANICS
GRANULAR MATERIALS
HYDRODYNAMICS
PLASTICS
POROSITY
PRECURSOR
SHOCK WAVES
YIELD STRENGTH