Micro-Mechanism of Spherical Gypsum Particle Breakage under Ball–Plane Contact Condition

Abstract

Coarse-grained soils are used extensively in engineering applications. The breakage of coarse-grained soil particles may have a great effect on their mechanical characteristics. It is important to fully understand the phenomenon of particle breakage and comprehend its effect on engineering properties. The aim of this study was to investigate the process and mechanism of spherical particle breakage under ball−plane contact conditions. Particle contact tests and corresponding simulations based on the discrete element method were performed. The mechanical properties and breaking morphologies of gypsum balls, as well as the significant feature of the existence of a cone core under the contact point, were obtained by the experiments. To enable particle crushing in a numerical simulation, noncrushable elementary particles were bonded together to represent the specimen. The numerical model, which was validated by the unconfined compression test and splitting test, was well fitted with the experiment by applying flat-joint contact. More importantly, the combination of the simulation and experiment demonstrated the role that the cone core plays during particle breakage and revealed the mechanism of the formation of the cone core and its effect on particle breakage.

Keywords

• particle breakage
• cone core
• discrete element method
• flat-joint model