Development of a granular normal contact force model based on a non-Newtonian liquid filled dashpot

作者：Alizadeh Ebrahim; Bertrand Francois^*; Chaouki Jamal

来源：Powder Technology, 2013, 237: 202-212.

DOI：10.1016/j.powtec.2013.01.027

• Normal contact force model
• Coefficient of restitution
• Collision time
• Discrete element method
• Non-Newtonian fluid

Normal contact force models often suffer from a weak prediction of collisions between particles. They regularly fail to predict an adequate energy restitution behavior with increasing normal impact velocity. In particular, most non-linear models predict a net attraction force between two impacting particles near the end of a collision, which is unrealistic according to reported results. Such limitations have provided the impetus for the development of a normal contact force model that better predicts the unfolding of a collision between two particles. This model comprises a Hertz elastic force and a dissipative force that is evaluated by the motion of a non-Newtonian liquid in a dashpot The model parameters are set using experimental restitution data for particle/particle and particle/wall contacts. In the current work, the measurement of energy restitution for particle/wall collision was carried out using several materials over a wide range of impact velocities, whereas particle/particle collision data were obtained from the literature. Model predictions for microscopic (e.g. particle velocity) and macroscopic (e.g. collision time) quantities are presented and compared with those from other non-linear models and experimental data. The model is observed to adequately,predict the coefficient of restitution and to decrease the attraction force at the end of a collision.

• 出版日期2013-3