Shock propagation through alumina observed at the mesoscale.

The shock response of 88% and 99.9% pure aluminas, chosen since they had been tested previously, was simulated at the mesoscale. Microstructures were investigated using electron microscopy and then digitized for use in simulation. These microstructural units were stacked to recover larger-scale structures generated randomly. These extended the length ranges in the simulations from the micrometer to the continuum scales. Modeling emphasized the inhomogeneity of the flow at this length scale and phenomena such as precursor decay were accentuated in the material with the greater impurities. The bulk composite behavior could be recovered from the properties of the individual phases by adopting simple expressions for the shock parameters. These behaviors include the profile of the stress histories and quantitative prediction of the Hugoniot elastic limits recovered using information derived purely on constituents. [ABSTRACT FROM AUTHOR]