Abstract
A computer program TRUBAL was used to study fabric and shear modulus for sphere assemblies. It was shown by comparison with the experimental results that TRUBAL is able to describe the behavior of granular material qualitatively. The shear modulus was found to have a close relationship with the coordination number. During shear deformation, the coordination number decreased and the anisotropic fabric built up in the major principal stress direction, the sample became less rigid and its shear modulus decreased. After a cycle of loading and unloading, there was a net loss in coordination number and some remaining anisotropic fabric. This was also reflected in a decrease in the shear modulus. The isotropic fabric seems to have the highest coordination number. There is no unique relationship existing between the fabric and the stress or the fabric and the strain. The change of fabric appears after the change of stress takes place but it is ahead of the change of strain.
