Shock-wave stability in quasi-mono-disperse granular materials

Institute of Shock Physics, Imperial College London, London SW7 2AZ, UK

^a e-mail: w.proud@imperial.ac.uk

Received: 8 February 2011
Revised: 15 September 2011
Accepted: 14 October 2011
Published online: 15 February 2012

Abstract

This study investigated the stability of shock-waves in brittle granular materials and thus determined whether materials, such as sand, could be represented by a Hugoniot equation to describe their shock response. A series of plate impact experiments on quasi-mono-disperse soda-lime glass microspheres was conducted with the aim of measuring the shock-wave profile to determine if there was any change over time/run distance. Granular bed thickness and input stress were varied to study the effects of dispersion on shock-wave velocity (C_sh). It has been shown that it is possible to sustain steady shock-waves in brittle granular materials due to no measurable wave dispersion occurring in the samples tested. This study also highlighted an unsteady precursor wave that is present in the wave profiles at low stresses.