Insights into granular mechanics through neutron scattering

Neutron scattering techniques have provided a window into the structure and mechanics of solid materials for many decades. Recent work by the authors has demonstrated that these techniques can also provide tremendous insight into granular systems. Two prominent examples are presented; 1. The use crystallographic texture measurement techniques to uncover the evolution of fabric within clay soils as a function of deformation, and, 2. The use of neutron diffraction strain measurement techniques to examine the behaviour of force chain networks during the compaction of granular systems. In both cases, neutrons are able to provide quantitative measurements that are difficult (if not impossible) to obtain any other way. In the first case, this refers to the direct measurement of the average fabric tensor over a representative sample; in the second, neutrons are able to determine the three-dimensional stress state within individual particles and hence allow the calculation of the actual force network existing within an entire assembly of particles.