Static compression of a granular medium: the “soft shell” model
Collège de France - 11 place M. Berthelot, 75231 Paris Cedex 05, France
Accepted: 26 May 1996
An assembly of spheroidal particles in Hertzian contact should display an elastic modulus proportional to (where P is the pressure). We consider here a system where each particle (diameter d) is covered with a soft shell (thickness e, modulus μ) while the inside is rigid. This soft shell may, in practice, be an oxide layer. We then expect for a large range of pressures, in agreement with experiment. We also discuss the average conductance , assuming a small conductance in the soft shell, but ignoring tunnel effects. Then .
PACS: 82.70.-y – Disperse systems / 91.60.Ba – Elasticity, fracture, and flow
© EDP Sciences, 1996