Un modello discreto a deformabilità concentrata per strutture in muratura

A discrete model for the analysis of masonry structures, based on the use of rigid blocks joined by deformable discrete interface elements, is presented. The interfaces are modelled as plane cushions of springs with no resistance with respect to the normal tensile stresses and an elastic–perfectlyplastic behaviour with respect to shear stresses. The model is implemented into a numerical code and used to analyze two benchmark structures: (1) a circular arch subjected to self-weight and a quasi-statically increasing, vertical point-load and (2) a dry masonry wall subjected to inclined body forces. In the first structure, the failure is dominated by the no-tensile behaviour of masonry and the numerical results converge to the theoretical ones obtained for the ideal no-tensile–rigid material. In the second structure, the failure mechanism is mainly due to plastic-slip between blocks, where the interaction forces are suitably distributed by the stiffness of the interfaces; the numerical simulations show a good agreement with experimental tests. The sensitivity of the model to the interface parameters and to the discretization is also studied. For both examples a robust behaviour is observed.