PhD Candidate, Monash University


This research proposes a modelling approach that combines a discrete numerical method with continuum-based models to characterise damage in quasi-brittle materials. In this approach, Discrete Element Method (DEM) is employed as the numerical framework to simulate material cracking. Together with this, coupled damage-plasticity models based on continuum mechanics are proposed to describe the local responses of contacts between particles in DEM. This continuum-discrete modelling approach takes advantage of the appealing features of DEM in replicating the heterogeneous microstructure of quasi-brittle materials and modelling crack initiation and propagation. In addition, the development and implementation of constitutive models are simpler compared to the continuum methods, as these models only deal with the one-dimensional condition of contacts while the heterogeneous response of materials is directly mimicked by DEM. Numerical simulations show that the proposed modelling approach can capture closely the mechanical behaviour of quasi-brittle materials, evidenced by their good agreements with experimental results in both stress-strain responses and crack configurations. Moreover, the microstructural effects and hysteresis response featured in quasi-brittle materials can be naturally captured by DEM simulations. This demonstrates the effectiveness of the modelling approach for characterising damage behaviour in quasi-brittle materials, and also makes the potential to extend this method to other particle-based materials.