Parametrical study of rubble stone masonry panels through numerical modelling of the in-plane behaviour

This paper focus on the investigation of the behaviour of rubble stone masonry piers, with air lime mortar, loaded in their plane using nonlinear static parametric analysis. This investigation is crucial for the seismic assessment of existing old unreinforced masonry buildings in Lisbon, since there is a clear lack of data for the nonlinear characterization of this kind of masonry. Numerical analyses are performed by adopting the macro-modelling approach implemented in the DIANA software. The adopted procedure for model calibration consists on fitting its behaviour with the results of the performed experimental tests on rubble stone masonry piers with air lime mortar. The parametric analyses are carried out by varying the slenderness and thickness of the piers, as well as the axial load in order to evaluate the influence of such parameters on shear strength, displacement capacity and stiffness. A sensitivity analysis is executed to define the most appropriate size of the elements' mesh. A good agreement is obtained between the piers tested experimentally and its numerical counterpart models in terms of the force-displacement diagram, damage pattern, failure mode and dissipated energy. In addition, the comparison in what concerns both ductility and energy dissipation is also presented for different cases. The results attained by numerical parametric analyses are presented and discussed along with the main conclusions.