Improvement of viscoelastic damping for the Hertz contact of particles due to impact velocity

Abstract

One of the most important task in application of the Discrete Element Method (DEM) to simulation of geomaterials is the adequacy of description of contact between interacting mineral particles. In most of the cases the elastic force is expressed by using Hertz model, while description of viscoelastic damping force is still under discussion. Recently various damping models described by different values of overlap power factor are used in DEM calculations. The general form of viscoelastic damping constant was presented, where well-known damping models present particular cases of general relationships. It known no one already existing models can precisely represent experimental results in most of the cases. In this paper general damping model comprising several existing approaches is developed. Here displacement power factor is evaluated on the basis of experiment results. It was found that the proposed approach gives more accurate simulation results of coefficient of restitution in comparison to already existing damping models.