Smoothed particle hydrodynamics for cohesive dense granular media

Abstract

• An elastic–viscoplastic constitutive model for cohesive dense granular media is built. • Rheological model considering cohesion for liquid-like phase is put forward. • The solid-like phase and liquid-like phase are both modelled and simulated. • Smoothed particle hydrodynamics was first used for cohesive dense granular media. • Cohesive force plays an important role in granular pile collapse, flow and depositing. Dense granular media with cohesion exist widely in nature. A constitutive model that considers cohesion in terms of solid-like and liquid-like phases in dense granular media was designed in this study. In this new model, a linear elastic–plastic constitutive relationship based on the Drucker–Prager yield criterion affected by the parameters of cohesion was used to describe the solid-like phase. A viscoplastic constitutive model based on rheology, which also considers cohesion, was obtained through formula derivation for the liquid-like phase after plastic yielding. The conversion and transitional relationships from elastic to elastic-micro viscoplastic and then to complete elastic–viscoplastic were built. Smoothed particle hydrodynamics was adopted to solve the new model discretely, and the relationship between smoothed and actual particles and an approach employed to avoid particle aggregation caused by cohesion were illustrated. Several typical cases including the collapse of cohesive granular accumulation, collapse of dry and wet granular column, and flow of cohesive powder in a rotating drum were used for verification. A comparison between cohesive and dry granular flows and among numerical results, experimental results, and those of other numerical methods proved that the proposed model and algorithm are effective for simulating dense granular flow with cohesion; further, they provide a valid approach to describe issues of granular flow with veritable cohesion that exist in nature.