Comparative study of analytical methods for Hugoniot curves of porous materials

This study compares five methods to compute Hugoniots for porous materials, with experimental data for porous copper. The methods compare well when porosities are low. Three methods model shock velocity versus particle velocity data over a range of porosities with reasonable accuracy. P-upsilon data are much more discriminatory and only two methods reproduce experimental data at high porosities with some degree of accuracy. Comparisons are made by plotting analytical results on curves fitted through experimental data points. Above certain porosities Hugoniot curves display anomalous behavior where (dP/d upsilon)>0. A new method is presented which contains only two parameters {K-T, and [(partial derivative K-T/partial derivative P)](T)} and which models both normal and anomalous Hugoniots curves. (C) 1999 American Institute of Physics. [S0021-8979(99)02915-1].