A damage bond model to investigate the damage and crack propagation for cemented materials and parametric analysis

In this study, a new contact model based on the particle discrete element is proposed to study the damage and crack propagation for cemented materials. The damage variable is defined by an equivalent displacement, considering the combined effect of the contact force and moment. The damage bond model is verified by theoretical calculation and numerical analysis. A three-dimensional discrete element model for cemented materials is established to simulate the unconfined and confined results. It was found that the simulation results are in reasonable agreement with the test results. The damage evolution, crack propagation, damage heterogeneity, elastic strain energy, and dissipated energy of the bond at different stages of the stress-strain curve are studied at the meso level. Following the parametric analysis, the damage evolution coefficient has significant effects on the peak stress, the peak strain, and the decreasing rate of stress after the peak stress. Moreover, the damage evolution coefficient greatly impacts the number and distribution of cracks, the elastic strain energy, and the dissipated energy. It will be shown that the damage bond model can provide a reference for the study of macro and micro damage fracture behaviors and progressive failure mechanisms for cemented materials.