A Continuum-Discrete Multiscale Model for In-Plane Mechanical Modeling of Masonry Panels

A multiscale numerical model for the in-plane mechanical behavior of masonry panels is presented. At the microscale, masonry is modeled by rigid blocks interacting through plane, deformable interfaces. These may represent actual mortar joints or virtual preferential fracture surfaces of the blocks (e.g., vertical surfaces crossing a block and connecting vertical joints in the brick rows above and below the considered one). Damage parameters control the interface transitions from a cohesive linear-elastic phase to an elastic-plastic one (modeling frictional sliding and contact) and, eventually, to a completely damaged one. At the panel scale, the material is treated as a finite-element discretized Cauchy continuum, homogenizing the periodic microstructure. The model allows reproducing the main anisotropic nonlinear behaviors of masonry by finite element simulations at a reasonable computational cost. With respect to more traditional phenomenological continuum nonlinear models, a more direct use of experimental data for the quantification of the model parameters is possible. Moreover, these parameters are fewer in number, since part of the complexity of the material is represented by the explicitly modeled microstructural geometry.