Evolution of Fabric and Strain within Representative Elementary Volumes Inside A Shear Band by Tracking Grains of a Sand Specimen in Triaxial Compression

Abstract It has been shown in several different studies that the behaviour of sands in triaxial tests is, in contrast to common assumptions, not homogeneous and that, after the localisation of strain, most of the soil behaviour takes place inside the shear band. In this work, the evolution of fabric and strain is extracted from the evolving shear band with the help of representative elementary volumes (REV) and compared with other regions inside the specimen as well as the overall behaviour. The size of the REV is determined by analysing the evolution of the fabric variables and the strain inside cubic elements with increasing size. For this purpose, a set of grains is assigned to the elements at the initial state and the grains are tracked throughout the test. The REV is then placed in different regions of the specimen and the evolution inside and outside the shear band as well as the global behaviour is compared.