DEM analysis of cohesive granular shear flow using dynamic adhesion force model - Model validation for contact-dominated regime

When the DEM simulations are performed, the particle stiffness of the Discrete Element Method (DEM) is often reduced to reduce the computational cost. The Dynamic Adhesion/Cohesion Force Model (DAFM/DCFM) was proposed for adhesive/cohesive particles to make the effect of adhesion/cohesion force on the collisional motion of a particle with a reduced particle stiffness equivalent to that of the original system. This study validates the applicability of DCFM to the contact-dominated regime by means of a series of DEM simulations of two-dimensional simple shear flow of cohesive spherical particles. The results demonstrate that DCFM accurately represents the cohesive nature of the original system with respect to the fluid-to-solid phase transition of granular medium due to a reduction in shear rate, as well as the shear stress of the granular medium. It is demonstrated that the bond-breaking model proposed in the present study describes well the validity of DCFM in the contact-dominated regime.