DETERMINATION OF RELEASE ADIABATS AND RECENTERED HUGONIOT CURVES BY SHOCK REVERBERATION TECHNIQUES

Release adiabats and Hugoniot curves centered at shock states can be readily determined by impacting a projectile disk onto a stationary reverberation disk made of a linear elastic material of known shock properties. The reverberation disk may have a free back surface or may be backed by a buffer disk made of the specimen or some other material. The reverberation disk is very thin compared to the thicknesses of the other disks so that many wave reverberations occur in it during the experiment. Depending on the impedance of the reverberation disk relative to the other disks, each reverberation successively unloads, or loads, the projectile disk, thus establishing points on a release adiabat or on recentered Hugoniot curves of the specimen material. The technique is particularly valuable for measurements on compressible nonlinear materials, and it generates a large amount of information in a single experiment. Experiments have been performed with X-cut quartz, Lucalox, and 60°orientation sapphire reverberation disks which illustrate the technique, and results are presented for an epoxy resin and a porous tuff. © 1969 The American Institute of Physics.