A novel coarse-grained discrete element method for simulating failure process of strongly bonded particle materials

Abstract

Strongly bonded particle materials are widely used in energy engineering, geotechnical engineering and other fields. However, there is still a lack of an effective approach for large-scale DEM simulation of strongly bonded particle materials with low computational cost. To address the excessive computational cost in large-scale DEM simulation of strongly bonded particle materials, this study proposes a coarse-grained method based on energy density conservation principle, comprehensively incorporating multiple energy forms, including elastic strain energy, damping dissipation energy, and rolling friction energy. Scaling relations of microscopic parameters in the coarse-grained system are derived to ensure the conservation of all forms of energy density mappings within the spring and damping elements during the particle scaling process. Numerical simulations were performed on both cylindrical specimens and single-perforated plate models under loading compression using the developed coarse-grained method. Results demonstrate that the coarse-grained system accurately reproduces the key physical parameters of the original system, including failure modes, damage characteristics, energy density, and mechanical properties. In contrast, simulations without coarse-grained system exhibited significantly higher errors, with magnitudes ranging from several tens up to 130 times greater than those of the coarse-grained system, thus validating the accuracy and effectiveness of the proposed method.