Publications
Shock Wave Perturbation Decay in Granular Materials
A technique in which the evolution of a perturbation in a shock wave front is monitored as it travels through a sample is applied to granular materials. Although the approach was originally conceived as a way to measure the viscosity of the sample, here it is utilized as a means to probe the deviatoric strength of the material. Initial results for a tungsten carbide powder are presented that demonstrate the approach is viable. Simulations of the experiments using continuum and mesoscale modeling approaches are used to better understand the experiments. The best agreement with the limited experimental data is obtained for the mesoscale model, which has previously been shown to give good agreement with planar impact results. The continuum simulations indicate that the decay of the perturbation is controlled by material strength but is insensitive to the compaction response. Other sensitivities are assessed using the two modeling approaches. The simulations indicate that the configuration used in the preliminary experiments suffers from certain artifacts and should be modified to remove them. The limitations of the current instrumentation are discussed, and possible approaches to improve it are suggested.