CG-enriched concurrent multi-scale modeling of dynamic surface interactions between discrete particles and solid continua

The interaction between granular materials and deformable structures is relevant to many industries, such as mining, construction, and powder processing. Surface coupling between the discrete (DEM) and the finite element method (FEM) is commonly used to numerically describe particle-continuum interactions. Using a recently developed surface-coupling method, enriched by coarse graining, a micro-macro transition technique to extract continuum fields from discrete particle data, we study the time evolution of linear momenta and energies in various particle-continuum systems and their dependencies on the coarse-graining (CG) width, the support of the smoothing kernel. Via three numerical examples including (1) a dense granular flow impacting on a flexible obstacle, (2) a viscoelastic cube bouncing and resting on a frictional granular bed, and (3) a monolayer of particles flowing on a cantilever, we show that CG-enriched surface coupling not only leads to more accurate predictions but also reduces excess energies numerically generated by the coupling method, and CG is more effective as the particle-structure interaction becomes dynamic. By varying the CG width, we observe stronger attenuation, decreasing the magnitudes of high-frequency oscillations, facilitating stress relaxation in dissipative coupled systems, and that the identification of the optimal CG width is indeed problem-dependent.

Automated summary

The interaction between granular materials and deformable structures is important in various industries. A surface coupling method combining discrete and continuum methods is commonly used for numerical modeling. This study investigates the time evolution of linear momenta and energies in particle-continuum systems using a recently developed coarse graining method, and shows that it leads to more accurate predictions and reduces excess energies generated by the coupling method, particularly in dynamic particle-structure interactions.