RECENT ADVANCES IN METHODS FOR MEASURING THE DYNAMIC-RESPONSE OF GEOLOGICAL-MATERIALS TO 100 GPA

Modeling certain classes of hypervelocity impact events requires laboratory materials data for benchmarking purposes. These data include Hugoniot states, release paths and strength. Two classes of impact techniques have been employed for measuring equation-of-state properties for rocks and rock simulants These techniques both use velocity interferometer diagnostics. One, employing a sample-in-projectile geometry, provides high-precision Hugoniot data and continuous release trajectories for dry or water-saturated materials. The majority of the present experiments have been performed with this geometry. The other, employing a sample in-target geometry, provides loading path and Hugoniot data as well as limited release data. Materials studied by these two techniques have included a variety of tuffs, rhyolites, carbonates, grouts and an epoxy-alumina mixture. Uncertainties in the results from these techniques have been estimated by analyzing the effects of errors in observables and ancillary material properties.