Methodology for Evaluating Tamper Equation of State in Tamped RMI Experiments

Numerical models are often used to predict the behavior of a system undergoing shock compression. At the continuum level, material behavior is typically dominated by two constitutive equations: dynamic strength and equation of state (EOS), which must be individually defined for each material in the system. Traditionally, strength and EOS have been characterized through separate experiments. The tamped Richtmyer-Meshkov instability (RMI) is a more recent method that was developed to calibrate dynamic strength through a combination of experiment and simulation. In this work, tamped RMI experiments are performed and recorded using x-ray phase contrast imaging. To eliminate the need for a separate experiment, radiographs of the tamper’s shock compression response were analyzed to define both the dynamic strength and EOS of an epoxy, as well as the EOS of two liquids and alumina powder. Numerical simulations were run to validate the EOS extraction methodology.