Application of the 3D DEM in the modelling of fractures in pre-flawed marble specimens during uniaxial compression

Abstract

The results of modelling fractures in pre-flawed marble cylinder specimens under uniaxial compression are presented in this study. The discrete element method (DEM) was used to investigate crack propagation and coalescence in marble specimens with pre-existing open cracks at various angles to the horizontal. The results of numerical three-dimensional (3D) simulations were directly compared to laboratory investigations. Pure spheres and clumps composed of spheres mimicking marble were used in mesoscopic fracture estimates. The formation of wing and secondary cracks under load were studied. The influence of smaller grains and the ratio between contact cohesion and contact normal strength were investigated. The geometric qualities of the initial faults and the interlocking effect influenced the strength, post-peak response, and crack propagation patterns in the marble specimens. The computational and experimental results were found to be in satisfactory agreement. The DEM simulations showed that the results were significantly influenced by the ratio of cohesive to tensile normal contact stress. The results also showed a correlation with the particle shape (spheres versus clumps).