Abstract
Considering different energy dissipation mechanisms, many normal contact models have been proposed. However, the size effect and velocity effect of normal restitution coefficient (NRC) cannot always be accurately described. In addition, most of the normal contact models have unphysical tension stage for particles without adhesion during the simulation of particle collisions. Such problems limit the application of discrete element method (DEM) in particle dynamics. Given such limitations, the normal contact model proposed in the present work consists of a nonlinear Hertz spring and a size-dependent nonlinear dashpot, and the model parameters are determined by the NRC obtained in lab tests. Compared with other viscoelastic contact models, the current model can effectively alleviate the influence of unphysical tension force stage on the calculated results, satisfying the accuracy requirement of calculation, and accurately describe the size effect and velocity effect of the NRC of marble spheres at the same time. Besides, due to the viscous force, the contact time calculated by the current model is a little larger than the elastic contact time. The relationship between model parameters and particle size has been analyzed, which shows the law of K1 conforms to exponential decay law and the K2 conforms to hyperbolic tangent function.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
