Intense shock compression of porous solids: Application to wc and ta2O5

Abstract

Abstract. The intense shock states achievable within granular or porous solids can be quantified through the application of continuum thermodynamic models. Here emphasis is on distended and granular solids for the purpose of calculating compression paths. In the present paper thermo-physical relations are developed and applied to the shock compression of aerogels and powders. These materials were selected because of previous studies available in the literature and recent high-pressure test results obtained at the Sandia National Laboratories Z-Machine. The relations developed herein have been implemented in the Sandia Laboratories CTH code, specifically within a newly modified version of the P-λ equation of state. Analytic equations of state similar to P-λ are usually considered inefficient for hydrocode computation because of the many subcycle calculations needed to determine the pressure. However, the main advantage of this newly modified EOS is it allows for the easy creation of novel heterogeneous mixture models, which are usable from the low-pressure crush-up response to extreme pressure states. Comparison between numerical simulation using the new model and experimental data shows good agreement.

High-pressure shock behavior of WC and Ta2O5 powders.

“…The highest data point for the Cerac material is somewhat anomalous in this regard since a copper impactor and driver were used for that shot while aluminum was used for the AE and consolidated materials. Recently the P-λ model [Grady and Winfree, 2001;Grady et al, 2000], which was originally developed for porous materials and mixtures at low to moderate pressures, was extended to the high pressure regime where thermal effects become critical and materials can exhibit anomalous compressibility [Fenton et al, 2011]. The conventional approach of calculating the porous response based on an equivolume mapping from the reference curve will not work when the material exhibits anomalous compressibility since the mapping would be multi-valued.…”