LABORATORY TECHNIQUES FOR VERY HIGH PRESSURES AND THE BEHAVIOR OF METALS UNDER DYNAMIC LOADING

Particular attention is given to the production of very high pressures by colliding thin metal plates with stationary targets. Shock wave conservation equations are developed for this geometry that enable one to convert measurable quantities into equation of state data. Some results and techniques of high- pressure experiments are presented. Since the temperature rise behind a shock wave is not measurable, a brief description is given of how temperature estimates are made. Auxiliary experiments that support these calculations are also described. The hydrodynamic flow of the colliding plate experiment is outlined with attention given to the large dynamic tensions that can be produced. The effect of phase changes on the flow is also discussed, and it is shown how transition pressures can be determined by observing the freesurface motion of the target plate. The current work of several investigators on the elastic-plastic deformation of metal under dynamic conditions is reviewed and discussed with respect to calculational models and metallurgical studies made on shock-loaded specimens. (auth