Dynamic response of berea sandstone shock-loaded under dry, wet and water-211 pressurized conditions

摘要

A single-stage light-gas gun was used to perform shock-recovery experiments on211u001eBerea sandstone under dry, wet and hydrostatically water-pressurized conditions. 211u001eThe samples were impacted by flyer-plates to achieve stress levels in the range 211u001e1.3 to 9.8 GPa. The microstructure of the shocked samples was analyzed using 211u001escanning electron microscopy (SEM), laser particle analysis and X-ray computed 211u001emicrotomography (XCMT). The dry samples show strongly fragmented and irregularly 211u001efractured quartz grains with a considerably reduced porosity, whereas the wet and 211u001ewater-pressurized specimens show less grain damage and less porosity reduction. 211u001eDuring shock compression the water in the pores distributes the stresses and 211u001etherefore the contact force between the grains is reduced. The interaction 211u001ebetween the grains during the shock process was modeled by explicitly treating 211u001ethe grain-pore structure using Smooth Particle Hydrodynamics (SPH) and the 211u001eDisctrete Element Method (DEM).