Numerical simulation of granular materials flow in silo by modified distinct element method
Numerical simulation tests were carried out using the distinct element method (DEM) paying much attention to the micro-deformation mechanism of granular materials flow in a silo. To do this, a modified version of DEM (MDEM), which can take into account the effect of rolling resistance at contacts, is used since it provides a powerful tool to investigate micro-deformation mechanism of granular assemblies under quasi-static loading. By using the DEM and MDEM, two-dimensional dry granular-material flows in a silo are simulated. Based on the simulations, we reach the following conclusions: (1) friction coefficient, as well as rolling resistance at contacts, has much influence on the discharge rate of the granular materials in the silo, (2) along the side-wall the shear band is generated, (3) a column-like structure is also generated near the sidewall. The column-like structure supports the load of granular materials and prevents the discharge rate from increasing, like a liquid. According to the shear deformation in the shear band, the column-like structures are destroyed and re-generated.