Evolving Deformation Fields in Shallow Indentation of Granular Materials

Abstract The problem of indentation has myriad applications in the infrastructure industry, especially in design of shallow foundations. The framework offered by plasticity theory and metal working have been used to understand the mechanics of indentation. The results of a series of experiments on indentation of granular ensemble conducted inside a XRCT set up are presented here. The indentation was carried out in 3 stages – in both intrusion and extrusion directions and the evolving displacement was mapped. The region of deformation of the ensemble is localized around the indenter and reduces with increasing depth of indentation. Further, other microstructural parameter such as the coordination numbers, zones of localization, shear bands etc were all mapped through the indentation process – under both intrusion and extrusion.