Ryohei Seto, Robert Botet, Martine Meireles, Günter K. Auernhammer, Bernard Cabane
Compressive consolidation of particulate gels has been studied using a cohesive contact model with the discrete-element method in the quasi-static limit. The 2D simulation of uniaxial compression was applied to fractal networks, and the required compressive stresses were evaluated for a wide range of packing fractions \phi that approached close packing. The compression acts to reduce the length scale of the structures, that contribute to the network strength. We observed three stages of compression: (I) elastic deformations of percolation chains are dominant; (II) mesh-like domains, whose strengths are determined by a rolling mode, span from the top to the bottom; and (III) smaller meshes, or lamps, which can be destroyed not only by rolling moments but also by pull-off and sliding forces, span from the top to the bottom. The transitions are characterized by different power laws in the Py-\phi constitutive relation. We also examined how the compression changes the fractal dimension Df and the correlation length \xi. It tunes out that both fractal characteristics start to change from the early stage of compression, which is different from the usual assumption in theoretical models.
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http://arxiv.org/abs/1301.4464
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