Measuring the fabric evolution of particulate media during load reversals in triaxial tests

The behaviour of granular materials upon load reversal is not yet fully understood. In order to experimentally reveal the microstructure of a specimen subjected to load-unload cycles, a triaxial compression test on lentils is carried out in the x-ray scanner. Before analysing the acquired tomographies, a benchmark analysis is conducted to validate the image analysis tools that are used to extract the fabric from these images. The contact fabric evolves strongly with the shearing in the experiment on lentils. However, only very slight changes of the anisotropy within the cycles are observed.