Granular Materials at Meso and Macro Scale: Photo-Elasticity and Digital Image Correlation

Combining integrated photoelasticity and high resolution particle image velocimetry (digital image correlation) provides a tool which can be used to study granular materials at different scales. We have used an experimental arrangement which subjects an assembly of small 3D glass grains to plane strain conditions at the macro-scale. While the quantitative interpretation of individual and incremental photoelastic images in terms of continuum stress quantities presents challenges, some comparisons of strain increment and qualitative stress increment data are presented with concentration on the regions of apparent strain localisation.