Shock Propagation Produced by Planar Impact in Linearly Elastic Anisotropic Media

Abstract

Plate-impact experiments and shock-wave propagation in isotropic materials have become a standard technique for the study of material properties at very high strain rates. Recent work has also included shock propagation in anisotropic materials for specific wave-propagation directions in which pure longitudinal motion can exist. In this work, the effect of anisotropic elasticity and its influence on plane-wave propagation for arbitrary loading directions in plate-impact experiments is studied. The analysis applies specifically to the propagation of elastic disturbances produced by planar impact in a series of anisotropic plates of dissimilar materials each of arbitrary crystallographic orientation. The boundary conditions that exist between adjacent materials as well as conditions at free surfaces are considered in detail. It is found that for general orientations of single-crystal Be and Ti (hexagonal symmetry), multiple-wave effects, and transverse particle motion resulting from the elastic anisotropy are small. However, for y-cut α quartz (trigonal symmetry) these effects are significant. Transverse velocity components have been found to be greater than 35% of the maximum longitudinal velocity component.