Modeling Dynamic Ductility: An Equation of State for Porous Metals

Enhanced heating from shock compression of a porous material can potentially suppress or delay cracking of the material on subsequent expansion. In this presentation we quantify the expected enhanced heating in an experiment in which a sector of a thin cylindrical shell is driven from the inside surface by SEMTEX HE (peak pressure $\sim $21.5 GPa). We first show the derivation of an analytical equation of state (EOS) for porous metals, then discuss the coupling of this EOS with material elastic-plastic response in a 2D hydrocode, and then discuss the modeling of the HE experiment with both fully dense and 10{\%} porous Ta and a Bi/Ta composite. Finally, we compare our modeling with some recent experimental data.