Correlating Parameters between Hertz Contact Model and Spring-dashpot Model for Simulation by Discrete Element Method

摘要

Estimation or determination of model parameters for discrete element method (DEM) is an area of growing interest with the objective of providing robust methods combining single particle and bulk measurements.DEM simulation is implemented by a spring-dashpot model from the contact model,which requires the stiffness and damping coefficient in the vibration system relating to the approaching distance and coefficient of restitution in contact law.The accuracy of the DEM simulation depends on the displacement,velocity,time-period and forces in the contact process predicting by the model.Several methods that commonly used in DEM simulation have been examined by the calculation of the displacement,velocity,forces and time-period,and we find some unrealistic behavior for most of methods commonly used.By relating the stiffness of the spring with Young's modulus of materials and approaching distance,and damping coefficient with displacement and coefficient of restitution,a nonlinear model is analyzed,which give realistic results for the displacement,velocity,time-period and forces in the contact process.