Insight into the fracture evolution behavior of pre‐flawed hollow‐cylinder granite under multi‐stage increasing‐amplitude cyclic loads: A lab‐scale testing

Abstract

Abstract The structural deterioration and associated fracture evolution behavior of pre‐flawed hollow‐cylinder granite subjected to multi‐stage increasing‐amplitude (MSIA) cyclic loads are studied herein. The influences of rock structure on volumetric deformation, damage accumulation, energy dissipation, and failure pattern were investigated. It is shown that the volumetric deformation is relatively large for rock having high flaw angle, and it is the minimum and maximum for rock having a 10° and 70° flaw angle. A damage evolution model that can describe a first fast and then steady damage propagation was proposed based on the irreversible axial strain. Much energy needs to be consumed to drive crack propagation and hole collapse for rock having high angle flaws. A series of 2D computed tomography (CT) images reveal the different crack network pattern and how it is affected by the rock structure. A more complicated crack network is found for rock having a high flaw angle.