Comparison of bonded-particle numerical model results with indirect tension experimental results for Dionysos marble

In this study, results from two series of indirect tensile tests on Dionysos marble specimens, the Brazilian test and the ring test, are compared to those evaluated numerically by using the distinct element code PFC2D. Circular disc specimens with a diameter of 54 mm were prepared and tested in the laboratory. Specimens with different hole diameters were tested with respect to the ring test. The numerical simulations of this study were performed using the Bonded Particle Model (BPM) in PFC2D. The initial selection of the BPM micro-parameters was based on diagrams relating the PFC2D parameters and the synthetic rock properties. The models were calibrated by numerically simulating uniaxial compression tests and Brazilian tests. The ring-test PFC2D models were developed with the same specimen geometries as those of the laboratory tests and by applying the calibrated BPM micro-parameters. The numerically obtained fracture loads are compared to those measured experimentally. Furthermore, the evolution of bonds breakage during the simulation is compared to the rock fracture patterns observed during failure of the specimens. The simulation results demonstrate that both the macro-mechanical response and the failure process can be modeled using BPMs. Differences between the numerical results and the macroscopic marble behavior are discussed.