Mechanical performance simulation and homogenization of masonry materials based on meso-scale discrete element model

This study developed a meso-scale discrete element model (DEM) for mechanical performance simulation of masonry materials. In this model, bricks and mortar were separately discrete as regular rigid elements and the interfaces between them were assigned with corresponding material properties individually. Poisson’s effect, multi-axial and normal-shear failure criteria were introduced in DEM to reflect material properties under combined stress state. The constitutive relationships and failure criteria of bricks, mortar and interfaces were obtained from material experiments. Explicit solution procedure was adopted which is especially suitable for nonlinearity and discontinuity problems. Compared with the tensile, compressive and shear experiments of masonry, it was confirmed that the proposed meso-scale discrete element model could well capture cracks under tension, Poisson’s effect under compression and shear-friction without or with normal stress. The calculation results with representative volume element (RVE) model considering the actual bond pattern of masonry provided reliable input data for further numerical analysis of masonry structures where the masonry materials are considered as homogeneous.