Large amplitude compression and shear wave propagation in condensed materials

Abstract

In the last few years experimental methods have been developed to produce and measure large amplitude one-dimensional compression and shear waves in impact experiments. Shear wave data have been obtained for materials ranging from elastomers (essentially liquids) to hard ceramics, like polycrystalline Al2O3. We can now measure “acoustic” longitudinal and shear wave velocities in the shocked region and better quantify the shocked state. For a certain class of materials, these measurements provide a complete specification of the stress tensor in shock wave uniaxial strain experiments. This was not possible in the past. Time-resolved amplitude measurements (particle velocity data) can be used to integrate the governing equations to directly provide longitudinal stress-volume (σ11−V) and shear stress-shear strain (σ12−ε12) relations. No prior assumptions about constitutive response or infinitesimal strain are necessary. Related developments with regards to piezoelectric transducers will be indicated. [Work supported by ONR.]