Modelling fracturing process using cohesive interface elements: theoretical verification and experimental validation
Bin Zhang, Sadegh Nadimi, A.-B. Eissa, Mohamed Rouainia
Abstract
The tensile strength estimated from the Brazilian test on brittle materials is highly dependent on the contact topology between sample and loading platens. Common topologies such as flat-to-point, arch-to-arch and flat-to-flat contacts have been proposed in the literature. By employing cohesive interface elements (CIEs), a finite element method (FEM) is developed in this paper to explore the fracture behaviour of samples using different contact topologies. The feasibility of adopting CIEs is verified theoretically using the crack extension test and validated experimentally using the Brazilian test. A mesh sensitivity and a parametric study are performed for model calibration. The simulation results demonstrated the good performance of the proposed CIEs and agreement with a range of experimental data in terms of stress–strain curves, strain distribution, crack initiation and propagation, and tensile strength. Based on the numerical results, it is concluded that the flat-to-flat contact topology is preferred for the Brazilian test due to its fracture behaviour that crack initiates at the centre of the disc and propagates toward the top and bottom, without any compression failure at the loading ends. This study provides a new conceptual numerical framework for fracture simulation and a promising way to assess the preferred contact topology for the Brazilian test.