Fast Algorithm of Distinct Element Method with Contact Force Prediction Method

Abstract

Distinct element method (DEM)requires enormous computation time because it needs small time increments that are sufficient to follow high frequency fluctuations in contact dynamic model. In general, the equations of motion of particles are solved by the second order Adams -Bashforth method, which estimates the contact force for the next time step by linear extrapolation, or by multistep methods such as predictor-corrector method. In order to overcome the deficit of conventional methods, we propose a Contact Force Prediction Method that allows us to use larger time increments. The method incorporates the contact force at every contact point obtained as the exact solutions or numerical solutions of differential equations that describe two particle contacts. It is confirmed that the proposed method gives the simulation results for packing and discharge of particles which are consistent with the experimental data, while accelerating DEM computation by 3 to 8 times.