(381c) Continuum Modelling of Cohesive Powder Flow

A continuum model implemented in the commercial finite element method (FEM) software Abaqus is used to model the powder dynamics of Avicel PH101 at low densities and low stresses, where the powder is able to flow. The modified Drucker-Prager Cap elastoplastic material model is used to model the powder. The results from shear cell testing and die compaction of Avicel PH101 are used to calibrate the plasticity-related material parameters. The elastic parameters are approximated from hydrostatic triaxial test data for Avicel PH102. A Flodex is used as a sensitive calibration experiment to resolve uncertainty in the four plasticity parameters at very low densities. The Flodex hole diameter in the simulations was set to the critical hole diameter that was experimentally determined. Then, a variance-based sensitivity analysis was carried out to determine how the amount of mass discharged from the Flodex as well as the mass flow rate is affected by varying the four parameters at low densities in the FEM simulations.