A Rate-Dependent Constitutive Model for Sand and Its FEM Application

It is well known that the deformation and strength characteristics of sand are very complicated, and time effects and strain localization are two of the most important aspects. A non-linear three-component rheology model consisting of a hypo-elastic component connected in series to a combination of non-linear inviscid and viscous components connected in parallel is proposed, which can take into account multi-factor influence on the deformation and strength characteristics of sandy soils. The inviscid component is described by an isotropic, energy-based hardening and softening, and non-associated energy model, while the viscous component is formulated based on the strain rate-dependent behavior of sandy soils. A finite element method (FEM) code incorporating the aforementioned model is validated by simulating the physical plane strain compression (PSC) tests on sand. It is shown that the proposed model can much better simulate the deformation and strength characteristics of sand, especially for the rate-dependent behaviors and strain localization into a shear band.