Analysis of wave profiles for single-crystal cyclotetramethylene tetranitramine

Abstract

Wave profiles measured in the β-polymorph of single-crystal cyclotetramethylene tetranitramine display the characteristic response of an elastic-plastic material, an elastic precursor followed by a plastic wave. Moreover, the elastic precursor decays with the length of run. Numerical simulations with a rate-dependent elastic-plastic model are used to account for nonlinear and transient wave behavior. In addition, to account for the measured anisotropy in propagation, parameters of an isotropic model are fit for two propagation directions, normal to the (011) and (010) planes of the P21∕n space group. Equation of state parameters are constrained by data for the longitudinal sound speed and hydrostatic compression. The fits show that the effective yield strength varies with direction from 0.18GPa for the (011) orientation to 0.31GPa in the (010) orientation.