A new model for the seismic performance assessment of masonry structures

The vulnerability and the low structural performance of masonry buildings under earthquake actions are well known. Considering that most of the architectural heritage of our country is of masonry, it follows that the study of seismic performances and the safety assessment of masonry structures assume a role of huge importance cultural, social and economical. Moreover, the inelastic behaviour showed from the material, already for low level of stress, involves that structural analyses and improvement techniques for recovery of masonry structures can be carried out by convenient nonlinear procedures. In this context the paper deals the proposal of a new constitutive model for the Finite Element Method (FEM) nonlinear analysis of masonry structures and the use of nonlinear static procedure in order to estimate the seismic performance of masonry buildings. In particular, the mechanical behaviour of masonry was simulated as a continuum homogeneous and isotropic material, using the concrete smeared-crack model modified by means of an interaction with the plasticity Drucker Prager domain and by means of the definition of a new compression failure surface. The calibration and validation of the FEM model was carried out by means of sensibility analysis of different mechanical parameters, based on experimental data available in literature. Finally the proposed material constitutive model was used for the seismic performance assessment of a typical example of masonry buildings.