Equation of State and Strength Properties of Selected Materials Under Extreme Conditions

Understanding the EOS and strength of these materials allows scientists to model planetary interiors and impact cratering events. Driven from a body-centered cubic ( ) phase to a hexagonal close-packed (

In reality, when a solid is subjected to a shock wave, the total stress tensor is split into the hydrostatic pressure (governed by the EOS) and the deviatoric stress (governed by strength models like Steinberg-Guinan or Johnson-Cook). As pressure climbs into the megabar (Mbar) range, the hydrostatic pressure vastly exceeds the material's shear strength, causing solids to physically flow like highly viscous fluids. However, retaining accurate strength models remains vital for capturing the exact timing of wave reflections, plastic work dissipation, and material failure. 2. Characterization Methods: How Data is Captured