A simplified homogenization-discrete element model for the non-linear static analysis of masonry walls out-of-plane loaded

The paper is focused on the macro-scale non-linear modeling of regular running bond masonry panels subjected to out-of-plane pushover analysis. The work is the point of convergence of two research lines: (i) one is focused on the development of an original meso-scale technique based on a heuristic homogenization approach for masonry panels; (ii) the other is devoted to the macro-scale modeling of heterogeneous materials by means of a specific rigid body and spring approach, RBSM. The meso-scale technique is based on a simplified kinematics in which each block is supposed to interact with its six neighbors by means of plane interfaces. In this way, the flexural and torsional moment-curvature constitutive relations in the non-linear field are obtained at the sectional level. Finally, the response of the masonry panel 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 occur. This combined approach entails a drastic reduction of the computational effort because the standard non-linear FE discretization is completely avoided both at a cell and structural level. The paper presents a validation through comparisons of the step-by-step pressure-displacement curves for masonry panels subjected to various geometry, constraints and flexion conditions. The good agreement found between present numerical results and literature data, suggests that the model may be a valuable tool for practitioners involved in the pushover analysis of masonry walls out-of-plane loaded. (C) 2010 Elsevier Ltd. All rights reserved.