Double-scale assessment of micro-mechanics based constitutive models for granular materials undergoing mechanical degradation

Abstract

The richness across the scales of geomaterials has long been known. Yet only recently, thanks to the development of new experimental techniques, it has been possible to study the micro (grain scale) origin of some of the phenomena observed at the macro (specimen) scale. This unprecedented insight calls for new models able to build rational links between these two scales. Some recently proposed models for cemented and uncemented granular materials take advantage of this understanding to conjugate the macroscopic irreversible strains with internal variables representing a statistically averaged evolution of the micro-structure. While these models have shown their capability to reproduce the macroscopic behavior of the geomaterials they were designed for, to fully assess them and to prioritize possible enhancements, a comparison between the predicted evolution of the micro-structure and appropriate experimental data is desirable. In this contribution we study the possibility of extracting robust and statistically meaningful measurements of microstructural evolution from X-ray computed tomography images which are then compared with the micro-scale predictions of the existing micro-mechanics based models.