Investigation on the mechanical behaviors of pre-cracked Brazilian disks using a trigon-based numerical manifold method

Abstract

In this study, a trigon-based numerical manifold method is developed to study the mechanical properties, including the crack propagation and coalescence process as well as peak compressive line loads of the pre-cracked Brazilian disks. An assemblage of trigon loops is adopted to approximate the microstructure of the rock-like specimens, based on which a modified cohesive contact model considering cohesion and tensile strength is used to interpret the fracturing behaviors of the cemented interfaces as well as the interactions between the initiated cracks. Firstly, numerical uniaxial compression test is carried out to calibrate the micro-mechanical parameters of the model. With the calibrated parameters, a series of numerical Brazilian splitting tests are conducted on the pre-crack disks including both single-cracked and double-cracked disks with varying crack inclination angles. Comparisons between the numerical simulations and laboratory results indicate that the mechanical behaviors of the pre-cracked specimens can be well predicted by the trigon-based NMM models.