Evolution of pore size distribution in deforming granular materials

Abstract

This letter presents the results of a numerical exercise in discrete element method focusing on the evolution characteristics of pore size distribution (psd) in granular materials under uniform deformation. The evolution has resulted from the microstructural rearrangement, in which contraction leads to disintegration of big pores into small pores and vice versa for dilation besides the swelling and shrinkage of individual pore spaces during shearing. The numerical analysis indicates the evolution of psd's towards a unique distribution when the granular assemblies are subjected to an identical boundary constraint. Primarily the variation in porosity during deformation governs the pore evolution characteristics, but the stress path also dictates the modal pore density. The nature of any psd, however, is found to be independent of the initial packing of the assembly and the current stress state.