Dynamical similarity in shock wave response of porous material: From the view of pressure

Under strong shock loading, the pressure distribution in porous material is very complicated. We simulate such a system using a mesoscopic particle method. Morphological analysis is used to characterize the high pressure regimes defined by P≥Pth, where PP is the local pressure and Pth a threshold value. The mean size of the voids embedded is about 10 μm. It is found that, the geometrical and topological properties of the high pressure regimes show high structure similarity S(t)S(t) and process similarity SPSP if the threshold Pth, porosity ΔΔ and shock strength vinit2 are appropriately controlled. For dynamical similarities in the same material, when the shock becomes stronger, the required pressure threshold Pth increases, but the increasing rate decreases; when the porosity becomes higher, Pth has a wider spectrum. For the dynamical similarities in different materials, in a wide range, the required Pth linearly decreases when the porosity ΔΔ becomes larger.