Torsion–shear behaviour at interlocking joints: Calibration of discrete element-deformable models using experimental and numerical analyses

An interlocking block is a concave polyhedron with non-planar joints connecting the blocks together. The possibility of the fracture within a masonry interlocking block is a major challenge that has remained rather unexplored yet. Different fracture scenarios can be taken into account through considering the crack planes at which the block can be set apart. The plastic failure inside the block can also be represented through the continuum plastic deformation of the block composed of continuum finite elements. For an interlocking block with a cuboid projection above (lock), this paper intends to analyse the torsion–shear behaviour of the lock experimentally and numerically based on the discrete element method. Two strategies are developed to model a concave block: the lock and main body of an interlocking block are set to be rigid and connected with a cohesive contact in between; the concave interlocking polyhedron is set to be deformable with elasto-plastic behaviour. Given the same material properties, the torsion–shear capacities of the lock obtained by the two numerical models and the experimental test are compared to each other. A parametric analysis is then provided to calibrate the deformable model.