Modeling shock recovery experiments of sandstone

Abstract

Abstract. We present results from mesoscale modeling of shock recovery experiments on Berea sandstone with the Smooth Particle Hydrodynamics and the Discrete Element methods. Each grain is represented with clusters of Discrete Element particles to provide explicit representation of the grain and pore structure. The grain structures simulate the structures observed using synchrotron micro tomography and Scanning Electron Microscope imaging. The modeling accounts for the influence of pore fluid and illustrates how grain/pore heterogeneity under dry and saturated states affects stress wave and grain damage behavior. The simulations show characteristics of the phenomena observed in recovery experiments. An increase in grain damage coincides with an increase in stress level and pulse duration. The grains in dry samples are extremely and irregularly fragmented with extensively reduced porosity. Less grain damage and higher porosity is observed in the saturated samples. The influence of pore fluid mitigates the interaction between grains, thus reducing fragmentation damage. This modeling approach in concert with experiments offers a unique way to understand dynamic compaction of brittle porous materials.

Computational design of recovery experiments for ductile metals

“…Shock recovery techniques have been developed over the past years using varying means of trapping momentum and different devices to introduce the pulse (Smith 1958;Dieter 1961;Zukas 1966;Mahajan 1970;Murr 1981;Mogilevsky & Newman 1983;Murr & Meyers 1983;Mogilevskii 1985;Meyers 1994;Llorca et al 2002). These techniques include design-orientation simulation to optimize target geometry (DeCarli & Meyers 1981;Rabie et al 1984;Tanaka et al 1984;Norwood et al 1986;Clifton et al 1990;Nellis & Gratz 1993;Hagelberg et al 2000). There have been also been attempts to recover brittle materials, and materials loaded in pressure and shear, but these are not considered here.…”