A micromechanical model for the confined uni-axial compression of an assembly of elastically deforming spherical particles

A micromechanical model of an assembly of elastically deforming spherical particles under confined uni-axial compression is described which is based upon percolating load-bearing strings of particles. This model leads to a prediction of the uni-axial compressive elastic modulus of the assembly and the ratio of the transmitted to the applied stress which is less than unity due to friction at the wall of the compression die. Experimental evidence is presented which supports the validity of the model. It is also shown that the approach considerably improves the predictive capability of models developed to calculate the tensile modulus of coherent particle assemblies.