Numerical Model for Granular Flow With Interstitial Fluid

ABSTRACT We present a constitutive model for the mechanical behavior of granular flow for both solid‐like and fluid‐like regimes. The stress rate tensor is decomposed into rate‐independent and rate‐dependent parts. The hypoplastic model is used for the rate‐independent part, while the ‐type rheological model is employed for the rate‐dependent part. The Stokes number is introduced to capture the influence of interstitial fluid viscosity within the rate‐dependent part of the model. The model performance is demonstrated through numerical simulations of element tests, encompassing both granular materials and granular‐fluid mixtures.