Comparison of coarse graining dem models based on exact scaling laws

Abstract

The simulation of a large number of particles requires unacceptable computational time that is the most critical problem existing in the industrial application of the DEM. Coarse graining is a promising approach to facilitate the application of DEM to industrial problems. While the current coarse graining framework is often developed in an ad-hoc manner, leading to different formulations and different solution accuracy and efficiency. Therefore, in this paper, existing coarse graining techniques have been carefully analysed by the exact scaling law which can provide the theory basis for the upscaling method. A proper scaling rule for the size of particles and samples as well as interaction laws have been proposed. The scaling rule is applied to a series simulations of biaxial compression tests with different scale factors to investigate the precision of the coarse graining system. The error between the original system and the coarse system shows a growing tendency as the scale factor increases. It can be concluded that the precision of the coarse graining system is accepted when applying scaling rules based on the exact scaling laws.