Hypervelocity impact of mixtures

Abstract

The study of the behavior of mixtures during shock loading entails several special problems which are both physical and computational in nature. On the physical level, many mixtures of interest such as engineering composites and water-saturated geological materials have consitituents which are both soft and porus. Thus hypervelocity impact produces enormous heating. The distribution of this heating between the constituents of the mixture must be understood before accurate predictions of Hugoniot states and release paths can be achieved. On the computational level, numerical solutions within a wavecode framework require simultaneous solutions of an equation of state and conservation of energy equation for each constituent of the mixture. At present, to achieve these solutions a numerical subcycling scheme is required. In this paper these problems are discussed in detail. A formulation of the theory of mixtures will be presented which is both complex enough to encompass the essential physics of many problems and simple enough to be incorporated into many wave propagation codes. Results of calculations will be compared to impact and release experiments on a mixtures of water and powdered calcite.