NUMERICAL SIMULATION OF THE BRAZILIAN TEST AND THE TENSILE STRENGTH OF ANISOTROPIC ROCKS AND ROCKS WITH PRE-EXISTING CRACKS

摘要

In the present study, an FEM/DEM coupled approach is used to simulate the fracture process in Brazilian tests. The study was performed using proprietary software to simulate both the intact rock behaviour and the development of fractures. Through the introduction of distinct elements with assigned contact properties, if the fracture criterion within the intact rock (represented by FEM) is met, then a crack (represented by DEM) is initiated. Adaptive re-meshing allows the fracture process through the FEM mesh to be tracked and visualized. In this study, Brazilian tests of rock samples with isotropic and anisotropic properties are simulated. Samples with pre-existing cracks are also investigated to find out the effect of preexisting cracks on the effective tensile strength of the rock samples. It is found that rock anisotropy and preexisting cracks (length and orientation) play an important role in determining the behaviour of tensile crack initiation and propagation, and hence the overall tensile strength of the rocks.