The effect of geometric characteristics on mechanical properties of asperities

Abstract

The deformation and failure behavior of fractured rock mass is closely related to the unevenness of the fracture surface. The deformation behavior of asperities on rough fracture surfaces has not been studied comprehensively. This paper aims to study the effect of geometric parameters on the mechanical properties of asperities under normal load. In this work, the uniaxial compression experiment using the discrete element software PFC3D was used to investigate the strength and stiffness law of asperities. The results show that compressive strength and stiffness are less affected by the height-width ratio of spherical asperities. However, the curvature of the asperities tip has a significant impact on the peak compressive strength and stiffness. As the curvature of asperities decreases, the peak compressive strength and stiffness rise. In addition, the strength and stiffness of the unevenness of the surface are also affected by the size effect. The peak compressive strength and stiffness increase as the size of the unevenness of the surface grows. The results show that the mechanical properties of asperities are significantly affected by the curvature and the size effect.