Elastic–plastic wave profiles in cyclotetramethylene tetranitramine crystals

The explosive molecular crystal cyclotetramethylene tetranitramine was studied in three orientations in a set of plate impact experiments; the orientations studied were 110, 011, and 010 in P21/n space group. The elastic–plastic shock response was measured using laser interferometry. The measured particle velocity profiles showed elastic precursor decay typical of a stress relaxing material. There is anisotropy in elastic shock strength and decay. The amount of precursor decay with propagation distance and stress relaxation behind the elastic shock varied among the orientations. The 010 orientation had larger elastic precursors than did the other two orientations; the 010 crystal does not have the regular plastic deformation mechanisms available to it. Elastic Hugoniots were obtained from the measurements. The inelastic deformation mechanisms may vary with orientation.