A New Approach to Model Irregular Particles Breakage with Deploying Image Analysis Techniques on Discrete Element Method

While the conventional Discrete Element Method (DEM) is a popular tool for investigating breakage, it falls short of accurately capturing the natural morphology of particles. Moreover, previously introduced techniques for simulating irregular particles' breakage have simplified the breakage into only two splitting and chipping mechanisms, which tend to depict fractures as linear or planar. To fill the research gap, therefore, we have introduced an innovative 3D breakage model that incorporates the actual shape of grains and all key breakage mechanisms, including splitting, chipping, and fragmentation. To consider all fracture mechanisms in our simulations, we deploy Dijkstra's algorithm within the particle's stress field to obtain the fracture surface(s). Following the identification of these fracture surface(s), we employ intersection set operations and a labeling technique to generate multiple sub-grains. To demonstrate the accuracy of our approach in modeling breakage, we compared our method to compression experimental data on a three-particle system. Our study involves quantitative analyses of volume, displacement, and rotational motions. Our results underscore the significance of particle displacement as a key factor in the breakage process while emphasizing the influence of rotational motion. Moreover, our findings effectively capture distinct stages of breakage and rotational movements. 1. INTRODUCTION Particle breakage can be seen in various industrial and/or research applications. In breaking systems, particles' pre-breakage and after-breakage behavior can influence the system considerably. To be more specific, the breakage can be seen in geotechnical (H. Y. Li et al., 2020; Z. Wu et al., 2019), ocean engineering (Shen et al., 2023), pharmaceutical (Picart et al., 2022; Xiao et al., 2022), etc. As mentioned, the breakage can happen on different scales. Although particle breakage in some cases is a micro-scale phenomenon, the change in characteristics of each system can lead to macro-scale change. For instance, the change in the shape of a grain in a pack of particles can change the stress distribution in such a system. Moreover, the change in the geometrical properties of a grain can add complexity to the problem due to the new contacts between sub-grains. Hence, understanding the breakage process is vital. Particle breakage has been divided into chipping, splitting, and fragmentation. When particles (i.e., sub-particles) have considerable size differences after breakage, the breakage is named chipping. However, splitting is the way of breakage where sub-particles have the same and/or close size; when a particle turns into several pieces, fragmentation breakage occurs. Comprehensive review on the breakage of granular matters can be found elsewhere (Tahmasebi, 2023).