ANALYSIS OF SHOCK-WAVE INTERACTION WITH POROUS ELASTIC-MATERIAL

One-dimensional interaction between a planar shock wave and porous mat erial with various porosity phi(g) are investigated numerically. As th e result of numerical investigations, it is deduced that the dynamic b ehavior of gas-foam interactions strongly depends on the porosity phi( g) of the foam. Four kinds of porous material are treated: rubber whic h is of no porosity (phi(g) = 0); foam 350 x 70 x 70 which is of low-p orosity (phi(g) = 0.76) and high density (rho(c) = 290 kg/m(3)); foam 50 x 50 x 50 which is of high-porosity (phi(g) = 0.98) and low density (rho(c) = 26 kg/m(3)); and foam 13 x 13 x 13, which has the same dens ity and porosity as foam 50 x 50 x 50, but has a different internal st ructure of foam material, In the no porosity (phi(g) = 0) and low poro sity (phi(g) approximate to 0 similar to 0.76) cases, comparisons of n umerical results with experimental ones show that the mobility of gas inside the materials is very low, and its dynamics can be approximated by a single-phase elastic motion. Results of single-phase analysis ar e compared with the shock tube experiments, which show essentially sam e stress variations with experimental results, In the high-porosity (p hi(g) approximate to 0.95) case, the mobility of the gas inside the fo am is higher, and the dynamics must be treated as. two-phase flow. Res ults of two-phase analysis simulate experimental stress variations in high-porosity foam well, while the single-phase analysis for high-poro sity foam dose not simulate experimental results well.