On the Determination of the Damping Coefficient of Non-linear Spring-dashpot System to Model Hertz Contact for Simulation by Discrete Element Method

The Discrete Element Method (DEM) is widely used in the simulation of a particle system. The viscoelastic contact models are the most common ones in the DEM simulation. However, these models stills have a few unrealistic behaviors, which will influence the reasonableness and accuracy of the simulation results. A general form of damping coefficient is proposed through dimensional analysis, and the condition is found so that the unrealistic behaviors can be solved. Regardless of adhesiveness and plasticity, an improved model based on Hertzian theory is proposed, in which the approximated expression relating the damping constant to the restitution coefficient is given. The impact of a single ball to a wall is simulated by using three different models, of which the results of contact force are presented and discussed.