A Nonlinear Elastic Model for Dilatant Coarse-Grained Materials

Abstract

Considering the coupling effect of the mean stress p and the deviatoric stress q on the deformation of coarse-grained materials, a nonlinear elastic K-G-J model that can account for the dilatancy and the intermediate principal stress of coarse-grained materials is established. The dilatancy equation derived from the microstructural changes of granular materials is introduced into the constitutive model to reflect the dilatancy of coarse-grained materials, and the strength nonlinearity of coarse-grained materials is considered by using a logarithmic relationship between the peak internal friction angle and the mean stress. Meanwhile, the SMP criterion is introduced into the model simply by using a transformed stress tensor, so that the model can reflect the influence of the intermediate principal stress. The model prediction of the triaxial compression and the extension tests on Toyoura sands agrees well with the experimental results, illustrating reasonability of the model.