Breakage Characteristics of Spherical Gypsum Particles under Three-point Contact

Abstract

Coarse-grained soil is widely used in various civil engineering. Particle breakage has a certain influence on its mechanical properties and engineering application. To study the breakage characteristics of coarse-grained particles under lateral pressure, the breakage characteristics of spherical gypsum particles under three-point contact were studied. The particle breakage experiments of spherical gypsum particles under three-point contact were carried out using Rock Rheological Testing System, combined with associated auxiliary fixtures. The contact mechanical properties and breakage characteristics of spherical gypsum particles were studied from the aspects of breakage process, breakage form, mass distribution after breakage, cone core and so on. It is found that under the condition of three-point contact, the spherical gypsum particles undergo integral fracture along the contact point line controlled by tensile stress. With the increase of lateral contact force, the vertical contact force decreases gradually when breakage occurs. The cone core was formed at the contact point when the lateral stress is high. The size of the cone core mainly depends on the contact force of the corresponding contact point, and is less affected by the contact force at other contact points. The stress state of the contact is analyzed and the breakage criterion in the case of three-point contact is established based on the Coulomb-Moore Criterion. It is proved that the breakage criterion is effective.