“…In a nutshell, in these models a crack is injected into Figure 2: Different boundary condition approaches, (a) uniform strain and (b) uniform stress boundary conditions the macroscale model when failure or instability occurs at the RVE. Please refer to the work of Massart et al [76,77] for the masonry cracking, Belytschko et al [21], Belytschko and Song [22] (the MAD method), Allen et al [123,124], Nguyen et al [91,89,90,136] for more details.…”