Internal states of model isotropic granular packings. II. Compression and pressure cycles.

摘要: This is the second paper of a series three investigating, by numerical means, geometric and mechanical properties spherical bead packings under isotropic stresses. We study effects varying applied pressure P (from 1 or 10 kPa up to 100 MPa in case glass beads) on several types configurations assembled different procedures, as reported preceding paper. As functions , we monitor changes solid fraction Φ, coordination number z, proportion rattlers (grains carrying no force) x0 distribution normal forces, level friction mobilization, near neighbor distances. Assuming contact law does not involve material plasticity damage, Φ found vary very nearly reversibly with an compression cycle, but all other quantities, due frictional hysteresis change irreversibly. In particular, initial low states high numbers lose many contacts end values z close those most poorly coordinated configurations. Proportional load variations which do entail notable configuration can therefore nevertheless significantly affect networks granular quasistatic conditions.