Macro-scale dynamic modelling of out-of-plane collapse of masonry façades accounting for texture quality

A two-step procedure for the dynamic analysis of large scale masonry façades constituted by the different type of multi leaf textures is presented. In the first step (meso-scale), a specific homogenization procedure is adopted to obtain macroscopic moment-curvature diagrams to use at a structural level (macro-scale). A Representative Volume Element (RVE) characterized by multiple leaves disposed along the thickness is considered. The blocks of the external leaves are modeled through parallelepiped elements, whereas mortar joints are reduced to interfaces with frictional behavior. All the non-linearity is concentrated on the interfaces and the computational effort required to obtain moment-curvature diagrams is drastically reduced if compared to a standard FE procedure. In the second step, heuristic flexural and torsional moment-curvature constitutive relations are used at a structural level, after their validation through results provided by the homogenization procedure proposed. Finally, the response of a masonry façade is computed at the macro-scale level by means of a mechanistic model, that is made by rigid elements jointed by spherical hinges and non-linear springs in which all the plastic dissipation and the mechanical damages occurs (RBSM model). In order to assess the capabilities of the procedure proposed, a large scale masonry church façade is analyzed extensively and results are compared with those provided by the commercial code at the micro-scale level.