Discontinuum analysis of the fracture mechanism in masonry prisms and wallettes via discrete element method

This study proposes an alternative approach to modeling the failure mechanisms of brickwork assemblages under combined shear–compression, shear–tension (parallel to bed joints), and compression–flexural loadings using the discrete element method (DEM). In this context, recently developed elastic-softening contact constitutive laws considering the mode-I and mode-II fracture energies are implemented into the dynamic solution scheme of the DEM to simulate the mechanical interaction between mortar and masonry units represented via 3D polyhedral blocks. Different experimental studies from the literature are used to validate the proposed computational models, and good agreement is found in terms of strength, material behavior, and fracture mechanisms. The findings of this research indicate that the proposed modeling strategy is successful in predicting the macro behavior of masonry under various complex fracture modes based on the defined micro properties. Sensitivity analyses are also performed by varying the fracture energy and valuable inferences are made with respect to the stress–displacement response and failure mechanisms of masonry.